Scientific CalculatorA free scientific calculator with real fractions, a graph, an equation solver, matrices, statistics, finance, 100+ formulas and a unit converter. It needs JavaScript to run; nothing you type leaves your browser.

Scientific Calculator ?

Rad2π

2nd

Deg

a/b

°′″

(

)

MODE

x²

x³

y^x

1/x

√

^x√y

sin

cos

tan

sinh

cosh

tanh

log

e^x

abs

nCr

nPr

Rand

Ans

DEL

–

+/–

raad.dev

List Pairs Separator Clear

Graph Table Examples Clear

y = y′

Solve Calculus Probability Finance

Matrix Complex Integer Computer

Variables Formulas Constants

Units Dates

History Clear

Scientific Calculator v 2.5

Number format

Choose how numbers look: results rounded to fixed decimals, scientific (1.23e+4) or engineering (12.3e+3), and how thousands and decimals are written. Auto places show as many digits as each result needs.

Variables, formulas and constants

A button at the top left of the display. It opens on Variables, the ten variables A to J and what each holds, then well-known formulas of geometry, physics, money and more, and constants of math and science, all searchable. Fill in a formula's letters to put it into the display, where you can still change it.

Converter

A button at the top left of the display that converts units of length, area, volume, mass, temperature, speed, time, data, pressure, energy, power, angles and fuel economy. The result shown is the value to start from; click a converted value to put it into the display. Its Dates tab counts the days between two dates and moves a date on by years, months and days.

Graph

A button at the top left of the display that draws up to seven functions of x, such as x^2 – 3 or 2sin(x), on x and y axes, with their roots, highs, lows and crossings marked. Drag to move it, scroll or pinch to zoom, and point at a curve or a dot for its values; the Table tab lists them.

Solve

A button at the top left of the display that solves an equation or an inequality for x, a polynomial, two or three linear equations or two curves, finds turning points, integrals, slopes, sums and products to ∞, limits, Taylor series, areas between curves, arc lengths and differential equations, the chances of the normal, t, χ², F, binomial, Poisson and other distributions, confidence intervals, and money over time, NPV and IRR, loans and savings, APR and APY, bonds, depreciation, break-even, inflation and percentage change.

Statistics

A button at the top left of the display: type or paste a list of numbers for its count, sum, mean, standard deviation, quartiles, median and more, with a histogram and a box plot; or pairs of numbers for their line of best fit and correlation.

Numbers

A button at the top left of the display for matrices: their determinant, inverse, powers, sums, products, eigenvalues, rows reduced, LU and QR, and A x = b, up to 10 × 10, and vectors; complex numbers, such as (2 + 3i)(1 – i), and the roots of polynomials of them; whole numbers in bits with their hexadecimal, octal and binary, numbers in any base, text as its codes, and numbers as doubles and floats; and whole numbers' prime factors, GCD and LCM, modular arithmetic, primes, numbers to every digit, fractions and their decimals, and rounding.

Features

Light, super fast and nothing leaves your browser.
Equation line: the display shows the whole equation while you type it. After the equation sign it shows the result, with the finished equation on a small line above.
History: click the clock at the top left of the display to see your past calculations. Insert an equation or a result into the display again, copy it, or delete it. It is kept when you close the calculator. Export, the arrow beside Clear, copies it all as text or saves it as a CSV file for a spreadsheet, or as a text file.
DEL button (or Backspace) to take back the last key you pressed, one key at a time.
Cursor: click into the equation, or use the arrow keys, to fix a number or an operator in the middle of it. Back at the end, the calculator goes on as before.
Variables, formulas and constants: the variables A to J, some hundred formulas to fill in and sixty constants of math and science. See the "Variables, Formulas and Constants" section below.
Converter: units of length, area, volume, mass, temperature and more, and dates. See the "Converter" section below.
Graph: functions, equations, inequalities, sequences, slope fields and points drawn, with their roots, highs, lows and crossings. See the "Graph" section below.
Solve: every root of an equation, in exact form as well, inequalities, turning points, polynomials, linear systems, two curves, integrals, slopes, sums, limits, Taylor series, differential equations, probability, confidence intervals, money over time, NPV and IRR, loans and savings, bonds and depreciation. See the "Solve" section below.
Statistics: count, sum, mean, standard deviation, quartiles, median and more of a list of numbers, and the line of best fit of pairs of them. See the "Statistics" section below.
Numbers: matrices up to 10 × 10 and their eigenvalues, vectors, complex numbers, bases and bits, text and its codes, IEEE 754, prime factors, modular arithmetic, primes, exact numbers, fractions and rounding. See the "Numbers" section below.
mod, gcd and lcm on the 2nd layer of %, ⁿC_r and ⁿP_r.
floor and ceil on the 2nd layer of abs and x!, side by side, and round on that of Rand: a number to the whole number below or above it, and to the nearest, half away from 0. They can be pasted too, with trunc, which goes toward 0: floor(7.5) = 7.
10^x, e and log_y (the logarithm to any base: 8 log_y 2 = 3) on the 2nd layer of log, π and y^x.
Degrees, minutes and seconds: the °′″ key shows results as 36°52′11.63″, and DMS in the display shows it is on. Paste an angle written so, 12°30′15″, 12°30'15" or 51°30′26″N: alone it shows as written, and DMS turns on. In an equation it is a number of degrees, and sin, cos and tan of it are worked out in degrees whatever the unit in use: sin(30°) is 0.5 in Rad as well. The converter has degrees, minutes and seconds among its angles too.
Fraction mode: the a/b key draws each division as a fraction while you type, and shows results like 0.75 as 3/4.
Number format: Fix, Sci or Eng notation with Auto or 0 to 9 decimal places, and thousands separators: 1,234.5, 1 234.5, 1.234,5 or 1 234,5. With the last two the decimal mark is a comma: the point key types it, and what you copy and paste is written so too. MODE goes from one notation to the next; the places and the separators are on the Options tab.
Function keys before the number, √ 9, as most calculators do; x², x³, x!, 1/x and % go after it or before it, 5 x² or x² 5. A key of two numbers pressed first, as nCr, takes the last result.
Memorizes not only the display if turned off/on but also all other states. It's even possible to continue a calculation sequence after turning computer off/on.
Full Keyboard support: See "Keyboard Support" section below.
Click the ? button at the top of the calculator to show or hide this page on a small screen.
Copy/Paste from/to display with Ctrl+C and Ctrl+V, or right-click the calculator and choose Copy or Paste. You can paste a whole equation, such as 2 + 3 × sin(30), not only a number.
Ctrl+Z (⌘Z on a Mac) undoes the last change to the equation: a key, DEL, a paste or a mode. Ctrl+Shift+Z redoes it.
Ten letters, A to J, each keep a value, as on a TI or a Casio. Alt+A (Option+A on a Mac) is STO→ A: type 5 + 3, press Alt+A, and 8 is kept in A; > then Shift+A does the same. Shift+A to Shift+J put a letter in the equation, 2A + B, worked out with what it holds. The Variables tab, the first tab of the formulas and the one it opens on, lists them, and a right-click on the display, a value of a panel or the history has Store in Var; on the display, Insert Var puts one in. They work in pasted text, the graph, the solver and the boxes of a formula. EE shows as ᴇ, 5ᴇ3, so 2E is 2 × E.
Dynamic font-size in display to keep numbers as readable as possible. An equation that is still too long can be dragged left and right.
Real sci-calc-style calculations, so 1+2*3=7 (... not 9 like with others),
and 1*(2+3)=5=25 (... not 8 like with other calculators).
Parentheses can be nested up to 29 levels deep.
No need to close parentheses if equation sign follows anyhow.

Variables, Formulas and Constants

Click fx at the top left of the display. It has three tabs, Variables, Formulas and Constants. It opens on Variables the first time, then on the tab you used last; Reset all puts it back on Variables. Formulas and Constants each have a search: type a few words, area circle or interest, and only what has them all is listed. Enter in the search opens the first one found.

Variables has a card for each of the ten variables, A to J, as the keys of a TI or a Casio have. Type a value in its box, press STO to keep the result of the line in it, or its arrow to put it in the equation, where it stays A and is worked out with what A holds then. Clear all sets every one back to 0. The keys are Alt+A (Option+A on a Mac) to store and Shift+A to put in, and a right-click has Store in Var and Insert Var.
Any box that takes a number takes A to J as well, a formula's, the converter's, the graph's and the numbers': 2A is 2 × A. Rest the pointer on one to see what its variables hold.
Some hundred formulas, by group: algebra, geometry, trigonometry, motion and forces, matter and energy, waves and light, electricity, chemistry, statistics, money and everyday ones. The quadratic formula, the volume of a sphere, the law of cosines, Newton's second law, Ohm's law, pH, compound interest, a loan payment, a price after discount, body mass index or a bill split among friends.
Rest the pointer on a formula to see what it gives, what each of its letters stands for and an example: a = 1, b = −3, c = −4 gives 4.
Click a formula for a box for each of its letters. A result in the display is already in the first box, to start from. Enter in a box goes on to the next empty one.
Insert, or Enter once all are filled, puts the formula into the display with its letters filled in, as an equation you can still change before =. Into an equation you are typing it goes in brackets, as one part of it.
Values with no answer stay in the boxes, and the formula says why in place of Error: "No real roots: b² − 4ac is below 0."
A formula with angles takes them in the unit in use, Deg, Rad or Grad, and says so under its boxes.
Some sixty constants, by group: math, universal, atoms and particles, heat and chemistry, and Earth and space. π, e and the golden ratio, the speed of light, the Planck, Avogadro and Boltzmann constants, the mass of the Earth, the Moon, Mars and the Sun, a light-year and more, those of physics from CODATA 2022. Each shows its symbol, its value and its unit; click one to put it into the equation as a number, in full and not only the 12 digits shown.

Converter

Click the arrows at the top left of the display. Pick what to convert and the unit your value is in, and the list shows it in all the other units of its kind at once, worked out as you type.

Thirteen kinds: length, area, volume, mass, temperature, speed, time, data, pressure, energy, power, angles and fuel economy. From millimeters to nautical miles, teaspoons to US and UK gallons, kilobytes to tebibytes, calories to kilowatt-hours, horsepower, knots, and miles per gallon to liters per 100 km.
The result in the display is the value to start from.
Click a converted value, or press Enter for the first one, to put it into the equation. Right-click one to copy it, alone or with its unit.
Exact where a unit is defined exactly: an inch is 2.54 cm, a pound 0.45359237 kg. Very large and very small values are shown as powers of 10.
An angle can be typed and shown in degrees, minutes and seconds, 36°52′11″, as well as in degrees, radians, gradians and turns.
The kind, the units and the value stay for the next time.

The Dates tab beside Units has three cards, each opened with a click. Dates are written as your region writes them, 14/10/2026 in the UK and France, 14.10.2026 in Germany, 10/14/2026 in the US, and typed so, or as 14 Oct 2026 or 2026-10-14. A click in a box of a date, its button or the arrow down opens its calendar, its weeks starting on your region's first day; an empty box is today. In the calendar the arrows go a day or a week, Page Up and Page Down a month, and Enter chooses.

Time between dates: first the years, months and days, 29 February 2000 to 14 October 2026 being 26 years, 7 months, 15 days; then the whole of it in each unit, 26 years, 319 months, 1,389 weeks, 9,724 days, the weekdays, Monday to Friday, both dates in, and the hours, each below 0 where the second date is before the first.
Add or subtract time: a date some years, months and days on, below 0 to go back, with its weekday, its day of the year and its week by ISO 8601. The years and months go first, and a month from 31 January is the last day of February.
Unix time, one way or the other. Unix → Date: the date and time of a Unix timestamp, 1700000000 being Tuesday 14 November 2023, 22:13:20 UTC, one of 13 digits being of milliseconds, in UTC, in the time here and in ISO 8601. Date → Unix: the timestamp of a date and a time, 14:30 or 2:30 pm, in UTC or the time here.
Click a number among the results to put it into the equation. The tab and the dates stay for the next time.

Graph

Click the curve at the top left of the display and type a function of x, as you would paste it: x^2 – 3, 2sin(x), 1/x or sqrt(x). The + at the top adds a box for another curve, up to seven, each in its own color, and the × in a box removes its curve.
Any other letter than x gets a slider: in a x^2 + b, drag a and b to see the curve change, or type their values and the ends of the slider; ▶ plays a slider, its value going from one end to the other and back with the curve, until you pause it.
Dots mark where a curve is 0 (its roots), its highs and lows, where it bends the other way (its inflection points), where it meets the y axis, and where two curves cross.
Drag to move the graph, scroll, pinch or use + and – to zoom, and the crosshair to go back to the start.
Point at a curve or a dot for its x and y, a round number near it going to it, 2 and not 2.04; click it for a popup where a click on its x or y puts it into your calculation (the popup goes three and a half seconds after the mouse is off it, and at once as you zoom, the point and its tangent staying; click the point to see it again), and on a curve the slope there as well, its tangent dashed across the graph. The arrow keys then trace it: ← and → move it along its curve, stopping at a root or a crossing, Shift ten times as far, and ↑ and ↓ take it to the curve above or below.
The button with a frame, under home, sets the view by typing where x and y go from and to. Off the curves, a click gives the x and y of that place.
For the area under a curve, press the button with a shaded curve, under the zoom buttons, and drag along the curve from one x to another: the area to the x axis is shaded, below the axis counted down; started between two curves, it is the area between them; an end near a root or a crossing goes to it, else to a round number, and its popup inserts the area; type in its From x and To x for ends of your own. The graph does not move as you drag, but held at its left or right side it slides on that way, the area growing with it. The button stays pressed for another area, until you press it again, double-click the graph, Esc, or zoom, home or the view.
Click a curve's y′ to draw its slope, the derivative, dashed in its color, or type d/dx before a function for its slope as a curve of its own: d/dx(x^2) is 2x.
An equation of x and y is drawn too, where its two sides are equal: x = 3, x^2 + y^2 = 25, x = y^2, its letters with sliders as well; point at it or click it as at a curve, for its x, y and slope, where it meets the axes and crosses a curve marked, and trace it with ← and →.
An inequality is shaded where it is true: y < x^2, x^2 + y^2 <= 9, x > 2, its line dashed for < and >, as its edge is not in it; two at once, 1 < x < 3, where both are.
A polar curve, r = 2sin(3θ), and a parametric one, (cos t, sin t), go once round, or as far as {from, to} after them says, r = θ {0, 6π}; click one for its θ or t, and trace it.
A sequence is drawn as a dot at each whole n: a(n) = a(n – 1) × 1.05 {a(1) = 100}, each term of the ones before it, its first terms in braces after it as a polar curve has its range; a(n) = a(n – 1) + a(n – 2) {a(1) = 1, a(2) = 1}; or a(n) = 2n + 1, of n alone. n goes from the first term given, or 1, for 50 terms, or as two numbers in the braces say, {1, 100}, up to 10000 terms. Any lowercase letter but x, e and i names one, and the same letter alone is still a slider. Point at a dot or click it for n and a(n), and ← and → go from term to term; a term too large to draw stops it, and one of a term before the first given is said in the note.
A slope field is drawn from dy/dx = x – y, or y′ = x – y, its slope a function of x and y: a short line at each place of a grid, at the slope there. The places its solutions start go in braces after it, dy/dx = x – y {y(0) = 1, y(0) = -2}, and each solution is drawn through its start, by the steps of Runge and Kutta; a click off the curves adds the one through there to the braces, and taking it out of them takes it away. Point at a solution or click it for x, y and its slope, and ← and → go along it; where one stops, as -x/y does where it goes straight down, the note says why.
Type points, (1, 2), (2, 4.1), (3, 5.9), and their fit draws the line nearest them, with its r²; click fit again for a parabola, an exponential (a · bˣ), a power and a logarithm, or the table button beside it to type them in rows of x and y.
Name a function, f(x) = x^2, and other boxes can use it: f(x) + 1, f(2x), or its slope f'(x) and f''(x).
Inequalities in braces keep a curve to where they hold, x^2 {0 < x < 3}, sin(x) {y > 0}; with a colon a function goes in pieces, {x < 0: -x, x^2}, the first that holds.
Where two equations cross is marked, and the area button finds the area inside an equation or an inequality too, as of x^2 + y^2 = 25.
Click a curve's colored dot to hide it and again to show it. The arrow down at the lower right saves the graph as a picture with its functions; right-click the graph to copy the picture instead. Pop out, the arrow out of a box beside Clear, makes the graph big: all of the window on the website, where pop in or Esc makes it small again, and in a window of its own beside the calculator in the extension.
The Table tab lists x and the y of each curve, and of a sequence its terms, n by 1 where there are only sequences, from a start by a step; left empty, they follow the view of the graph. Click a value to put it into your calculation.
The Examples tab has graphs to try, by group as the constants are: functions, sliders, equations, inequalities, polar and parametric curves, sequences, slope fields, pieces, functions named and points, then, last, fun pictures that move. Click one, or search and press Enter, and it is drawn in place of your curves.
Functions of an angle follow Deg, Rad or Grad.

Solve

Click x= at the top left of the display. Each tool is a card: open it, type in its boxes, and it is worked out as you type. Click a result to put it into your calculation, or rest the pointer on it to see it in full, with Insert and Copy.

Solve finds every root of an equation of x, x^3 = 2x + 1 or sin(x) = 0.5 (From and To say where to look), where an inequality holds, x^2 – 4 > 0 as x < –2 or x > 2 and in intervals, the turning points of a function, its highs and lows, the real and complex roots of a quadratic, a cubic, a quartic or a polynomial of any power up to 30, typed as (x – 1)(x + 2)^2 or as its coefficients, x, y and z of two or three linear equations, and x and y where two curves meet, x^2 + y^2 = 25 and x + y = 7. A root that has an exact form shows it as well: √2, (1 + √5)/2, π/6, ln 2.
Calculus has the integral of a function from a to b, an end of inf going on without end, its exact form, √π or 1/3, and the function's average there; its value and slopes at x and the tangent line there; sums and products for n from a to b, b inf as well, 1/n^2 from 1 on as π²/6; the limit of a function as x comes to a, from below and above, sin(x)/x at 0 or (1 + 1/x)^x at inf; its Taylor series about a, sin x as x – x³/6 + x⁵/120 – …; the area between two curves and the length of one from a to b; and y at x of a differential equation, y′ = x + y with y(0) = 1.
Probability has the normal distribution's chances, density and inverse; Student's t, χ² and F, their chances, p-values and the value for a chance; binomial, Poisson, geometric and hypergeometric chances; exponential and uniform ones; confidence intervals of a mean and of a proportion; and random whole numbers.
Finance works money out as a BA II Plus or an HP 12C does. Time value of money takes N, I/Y (a percentage a year), PV, PMT and FV, with the payments a year and each at the end of its period or at its start: leave one of the five empty and it is worked out, with all the money paid and the interest. Money received is above 0 and money paid below 0, so a loan of 200000 is PV = 200000 with PMT below 0; where the signs cannot balance, the note says so. NPV and IRR takes a rate and cash flows, one to a line or apart as the statistics list is, the first at the start: their net present value, internal rate of return, the one nearest 10% where the flows change sign more than once, and payback period. Loan calculator gives a loan's payment, its interest and a table of each year or, up to 600 rows, each payment, of the interest, the principal and what is left; Copy table copies it for a spreadsheet. Savings growth gives what money saved grows to, with interest m times a year and an amount added each period at its end or start if you like, all put in, the interest and a table of each year. Interest rates turns an APR into its APY for m periods a year, ∞ as well, and back. Bond price and yield takes the face value, the coupon a year, the years left and the coupons a year: leave one of Price and Yield empty and it is worked out, with the current yield and Macaulay and modified duration; years that are not whole coupons give the accrued interest and the dirty price as well. Depreciation gives what an asset loses each year down to its salvage value, by the straight line or the double declining balance, with a table of each year. Break-even gives the units to sell to cover the fixed costs and a profit if you like, what they sell for and the margin of each. Inflation brings an amount on by a rate a year, and back to money of today. Percentage change gives the change from one number to another, as a percentage of each: of a cost and its price, the markup and the margin. Money is shown to the cent; a click or Insert puts it in with every digit.
A box of a number takes a calculation too: pi/4, sqrt(2). What you typed stays for the next time.

Statistics

Click the bars at the top left of the display and type or paste a list of numbers, a column from a spreadsheet as well. Click a result to use it in your calculation, or rest the pointer on it for what it is and its value in full, with Insert and Copy. The list finds what is between its numbers by itself; choose new lines, tabs, spaces, commas, semicolons, pipes or colons at the top of the panel instead, and a number written 1,234.5, 1 234,5 or $1,200 is read whole.

List gives the count, the sum and the sum of squares, the mean, the standard deviation of a population (σ) and of a sample (s), the variance s², min, the quartiles Q1 and Q3, the median, max, the range, the interquartile range and the mode. The quartiles are found as a TI-84 finds them: the medians of the halves below and above the median, the median in neither. Under the results, a histogram of the numbers and their box plot.
Pairs takes x and y on each line, 1 2 or 1, 2, or two columns pasted from a spreadsheet, for their means, standard deviations, sums, Σxy and covariance, and the line of best fit by least squares, y = a + bx, with its slope, intercept, correlation r and r². The line is in the note under the box, and drawn through the pairs under the results.
Each tab keeps its own numbers, and both stay for the next time.

Numbers

Click the brackets with an i at the top left of the display. It has cards as the solver has, on four tabs. Click a result, or a number of a matrix, to put it into your calculation; rest the pointer on a result to see it in full, with Insert and Copy.

Matrix has a matrix of up to 10 × 10, its determinant, rank, inverse, transpose and power n, and the sum and products of two; its eigenvalues, real or complex, its characteristic polynomial and its eigenvectors; A x = b, linear equations of up to ten unknowns, all of their answers where there are many, x = p + t v, and the nearest by least squares where there are none; its rows reduced, its rank and null space; P A = L U and A = Q R. From 6 columns on its boxes and its results are smaller, to fit the card, each number of a result to as many digits as fit, the whole of it shown as you point at it; the eigenvalues of a matrix larger than 4 × 4 are found by the QR algorithm, and where a matrix is badly conditioned, as the 10 × 10 Hilbert matrix is, the note says how few digits of its inverse, determinant or answers can be trusted. A whole matrix pastes into a box of one, from there right and down: a block of cells copied from a spreadsheet, lines of numbers, or [1 2; 3 4] and [[1, 2], [3, 4]], the matrix made as big as it needs to be; and Copy on a matrix of results copies it, to paste into a spreadsheet or back into a box for the next step; each card's Example types in one to start from. And of two vectors, 1, 2, 3, their dot and cross products, lengths, the angle between them and the projection of one on the other.
Complex works out a complex number, (2 + 3i)(1 – i), sqrt(-4) or 2∠30 in polar form, for its real and imaginary parts, length, angle and conjugate and as r e^(iθ), and the n-th roots of one, each drawn on the plane; the roots of a polynomial of complex coefficients, x^2 + (1 + i)x + 2i; and the AC impedance of a resistor, a coil and a capacitor in series or side by side at a frequency, its size and phase, their reactances and the frequency of resonance, a value typed with a prefix as well, 4.7k, 10m or 100µ.
Integer has the prime factors of a whole number of up to 20 digits, 360 = 2³ × 3² × 5, whether it is prime, and its divisors; the GCD and LCM of two numbers or more; a mod m, a^b mod m, the inverse of a and every x of a x ≡ b (mod m), and the Chinese remainder theorem, 2 mod 3, 3 mod 5; a calculation to every digit, 100!, 2^200, 50 nCr 25, fib(300); the primes before and after a number, π(n), the n-th prime and the primes from a to b; a fraction, a decimal or 0.1(6) as a fraction, a decimal with the part that comes again in brackets and a continued fraction; and a number rounded to d places, half away from 0, down, up and toward 0, and to d significant figures.
Computer works out whole numbers as they are kept in 8, 16, 32, 64 or 128 bits: decimal, 0xFF, 0b1010 or 0o17, with + – × ÷, mod, AND, OR, XOR, NOT, shifts and ROL and ROR, shown in decimal, hexadecimal, octal and binary, and its bytes big-endian, little-endian and swapped. Bits shows each bit of a number, to turn over with a click, and how many are 1; IEEE 754 shows a number as a double and a float, 0.1 = 0x3FB999999999999A, what it is to its last digit, and the number of the bits of one. Any base writes a number of any base from 2 to 36 in another, the digits after its point as well, 0.1 as 0.0(0011) in base 2; Text and codes gives the code points, UTF-8 and UTF-16 of a text, é = U+00E9 = C3 A9, and a text of them; IP subnet gives the network of an IPv4 address, 192.168.1.10/24 or with its mask: its network and broadcast addresses, mask, first and last host and how many hosts; or of an IPv6 address, 2001:db8::1/48: the address in full and written short, its first and last address, how many addresses and /64 networks, its kind and its name for reverse DNS; UUID makes five new UUIDs of version 4, random, or of version 7, in order by time, each to copy, and reads one for its version, variant and the time it was made; Base32, 58, 64 and 85 writes a text in Base32, as the keys of two-step sign-in are, in Base58, as Bitcoin addresses are, in Base64, and in that of web addresses, or in Ascii85, and reads one back; and Hashes gives the MD5, SHA-1, SHA-256, SHA-512 and CRC-32 of a text, and checks a hash pasted against them.

Using the Calculator

Click on numbers and functions in Calculator just as you would with a standard calculator.
The display shows the equation as you enter it, so you always see the operation to be carried out. Click the equation sign and the display shows the result, with the finished equation on the small line above it. The opened parenthesis button keeps a ring around it until all parentheses expressions are closed.

If an equation gets too long for the display, its font gets smaller first. After that, press the line, hold it still for a moment, then drag it left or right to see the rest; dots (…) mark the side where more is hidden. A drag without the hold selects a part of it. On a touch screen a drag slides it, and a hold selects.
If a calculation is not possible (for example 1 ÷ 0), the display shows Error and the line above shows the equation that caused it.

This calculator uses an algebraic method of entry that allows you to enter mathematical sequences in the same order that they are algebraically stated (PEMDAS / AOS™).
PEMDAS: "Parentheses, Exponents, Multiplication or Division, and Addition or Subtraction". Multiplication and division have the same ranking. Addition and subtraction as well.

Keyboard Support

There is full keyboard support for each button on the calculator.

The numbers and + – × ÷ , . = keys can also be input on number block.
The keys are the same on a keyboard with no Latin letters, Arabic, Hebrew, Russian, Greek: a key gives what the key of its place gives on a US keyboard, so [s] is sin on the key of س and Shift+A, > and the digits work as they do on any other. A box of a panel, the converter's, a formula's, the graph's, takes them the same way: ٥ types 5 and Shift+ش types A, and a number pasted with ٣٫٥ is read as 3.5.
See below the keyboard shortcuts of each calculator button in [brackets].
Use the [Backspace] key or the DEL button to take back the last key you pressed: a digit, an operator, a bracket or a function. A finished result stays.
Hold key: [h, s] means: press h or H and you'll see a little 'hold' in the right bottom corner of the display.
This makes the followed key function different: [s] = sin, but [h, s] = sinh, etc.
Copy/Paste from/to display with Ctrl+C and Ctrl+V. Ctrl+C copies the result or, while you are still entering an equation, the equation as text.
Ctrl+V pastes a number (1,234.5, 1.234,5 and 1 234,5 are all read as 1234.5; 1.234 alone is read with the decimal mark the options set, and $1,200 or 5 USD as the number alone) or a whole equation, such as 2 + 3 × sin(30) or sqrt(16) + 2^3. If the pasted text contains an equation sign, it is calculated right away.
Double-click a number in the equation to select it whole, or drag over a part of it: what you type or paste then goes in its place, and DEL takes it out. A function key takes it as its number instead: sin over 30 is sin(30), √ over 2 + 7 is √(2 + 7) and x² over 2 + 3 is (2 + 3)²; pressed again straight after, it goes round that in turn: log, log over 8 is log(log(8)).
Right-click the display for a menu with Cut, Copy and Paste as well, and Reset all, which starts the calculator afresh: the equation and the memory cleared, 2nd, fractions and °′″ off, Rad, and what is typed in the statistics, the search of the formulas, the converter, the graph, the solver and the numbers cleared; the history stays. Copy takes the part of the display you selected, or else the result. The first time you use Paste there, your browser may ask you to allow reading what you copied; Ctrl+V works without that. The history, the formulas, the converter and the statistics have the menu too: Cut, Copy, Paste and Select all in a box you type in, Copy and Insert on a value.
All [ENTER] keys represent the '=' button.
Click Rad, Deg or Grad at the bottom left of the display to go on to the next unit, as the key does.
[←] and [→] move the cursor in the equation. [Home] and [End] go to its start and its end. On a result they do nothing: open its equation again from the history, or with a double click on the line above it.
History: click the clock at the top left of the display to see the calculations you finished with '='. Point at an equation or a result to show its two buttons on the left: insert enters the equation again, so you can change it or finish it with '=', or puts the result in as a number in the equation you are entering; copy copies it. A calculation with sin, cos or tan is marked with the unit it was done in, Deg, Rad or Grad, and is worked out in that unit again. A calculation done in fraction mode keeps its fractions, and one done with decimals keeps its decimals; inserting it switches fraction mode to match.

Standard Functions

DEL

[Backspace] Takes back the last key you pressed: a digit, an operator, a parenthesis or a function. Click it again to go back further, up to 50 steps. It does not change a finished result; use C or AC to start again. While the cursor is in the equation, it removes what is before the cursor.

[Del or Shift+Backspace] Click to clear the displayed number. Removes an incorrect entry/number from the display when pressed before any function or operation key is pressed.

[Del or Shift+Backspace] Click to clear the displayed number and the constant and pending operations.

[ENTER] Finishes any function or operation and displays the result.
If there are any unfinished parentheses expressions before this key is clicked or hit,
they get finished automaticaly. 2*(2+3*(2+4))=40 is the same as typing 2*(2+3*(2+4=40.

[*] Multiplys the value.

[/] Divides the value.

[+] Adds the value.

–

[-] Subtracts the value.

+/–

[#] Changes the algebraic sign.

Scientific Functions

[← →]

The cursor: click into the equation, or double-click the small line above a result, or use the arrow keys, to fix the middle of it. While the cursor is inside, keys write at the cursor as the equation reads: sin writes sin( and x² writes ², and DEL removes what is before the cursor. Back at the end ([→] or [End]), the equation is worked out again and the calculator goes on as always; = finishes it from anywhere. After a result, [←] enters its equation again and [→] puts the cursor at its start.

Deg

[d or °] Changes the mode to express trigonometric functions in degrees.

Rad

[d or °] Changes the mode to express trigonometric functions in radians.

Grad

[d or °] Changes the mode to express trigonometric functions in gradians, 400 to a full turn and 100 to a right angle: sin 100 is 1. The key goes from Rad to Deg to Grad and back to Rad, and names the unit it goes to next.

a/b

[f] Turns fraction mode on and off. While it is on (FRAC in the display), each division is drawn as a fraction as you type it: 1 ÷ 2 + 1 ÷ 3 shows ½ + ⅓, and = shows 5/6. Results are fractions whenever they can be one, with up to 10 digits; a number that is no fraction, like π or √2, stays a decimal. Copy gives a fraction as 5/6. The mode stays on until you click a/b again.

°′″

[h, f] Shows results in degrees, minutes and seconds: 0.6 sin^-1 is 36°52′11.63″ in Deg, and 2.75 hours is 2°45′0″. Click again for decimals; the number itself stays as it is. To enter an angle so, paste it: 12°30′15″ shows as written.

MODE

[o] Goes on to the next notation of results: Normal, Fix (1500.00), Sci (1.50e+3), Eng (1.50e+3, powers of ten in steps of three) and Normal again. The display shows FIX 2, SCI 2 or ENG 2 while one is on, or SCI and ENG alone with Auto places: as many digits as each result needs (1.5e+3), with Fix as Normal. The decimal places and the thousands separators are set on the Options tab, which follows the key.

2nd

[Space] Changes the trigonometric buttons (sin, cos, tan, sinh, cosh, and tanh)
to their inverse functions (sin^-1, cos^-1, tan^-1, sinh^-1, cosh^-1, and tanh^-1). It also changes ln to log₂, e^x to 2^x, log to 10^x, π to e, and y^x to log_y. Click 2nd again to return the buttons to their original functions.

(

[(] Opens a parenthetical expression. Expressions can be nested. Clicking on it lets a ring appear around the button to let you know that a parenthetical expresion is still active (until all expressions are closed with the closeing parenthesis or the equation sign).
A number right before the parenthesis is multiplied: 5 ( 2 + 3 ) is 5 × (2 + 3).

)

[)] Closes a parenthetical expression. The ring around the ( parenthesis key will stay until all expressions are closed with this key or after clicking the equation sign.

[%] Calculates percentages, adds markups, and subtracts discounts. On its own it divides the value by 100: 50 % returns 0.5. For example, to calculate 8% of 500, enter 8 % × 500 = which returns 40.
To add a markup or subtract a discount, use it after the + or – key. For example, to compute the total cost of a $500 item with an 8% sales tax, enter 500 + 8 % = which returns 540.

1/x

[\ or h, 1] Returns the reciprocal of a value in decimal format.

x²

[h, 2] Squares a value.

x³

[h, 3] Cubes a value.

y^x

[^ or ' or "] Click between values to raise the first value to the power of the second value.
For example, to compute 3⁴, enter 3 y^x 4 = which returns 81.

log_y

[h, ^] The logarithm to any base: enter the number, then log_y, then the base.
For example, 8 log_y 2 = returns 3, because 2³ is 8. (Available when the 2nd button is clicked).

[x] Calculates the factorial of a value: whole numbers from 0 to 170, and decimals as well (2.5! returns 3.32335…).

√

[h, r] Calculates the square root of a value.

^x√y

[r] Use between values to calculate the x root of y. For example to compute ⁴√81,
enter 81 ^x√y 4 = which returns 3. Odd roots of negative numbers work as well: ³√-8 returns -2.

log

[Shift+L] Returns the log base 10 of a value.

10^x

[h, Shift+L] Calculates 10 to the power of a value: 10³ is 1000. It undoes log. (Available when the 2nd button is clicked).

sin

[s] Calculates the sine of a value.

sin^-1

[Shift+S] Calculates the arc sine of a value. (Available when the 2nd button is clicked).

cos

[c] Calculates the cosine of a value.

cos^-1

[Shift+V] Calculates the arc cosine of a value. (Available when the 2nd button is clicked).

tan

[t] Calculates the tangent of a value.

tan^-1

[Shift+T] Calculates the arc tangent of a value. (Available when the 2nd button is clicked).

[l] Calculates the natural log of a value.

log₂

[h, l] Calculates the log base 2. (Available when the 2nd button is clicked).

sinh

[h, s] Calculates the hyperbolic sine of a value.

sinh ^-1

[h, Shift+S] Calculates the inverse hyperbolic sine of a value. (Available when the 2nd button is clicked).

cosh

[h, c] Calculates the hyperbolic cosine of a value.

cosh^-1

[h, Shift+V] Calculates the inverse hyperbolic cosine of a value. (Available when the 2nd button is clicked).

tanh

[h, t] Calculates the hyperbolic tangent of a value.

tanh^-1

[h, Shift+T] Calculates the inverse hyperbolic tangent of a value. (Available when the 2nd button is clicked).

e^x

[e] Raises the constant 'e' (2.718281828459045…) to the power of a value.

2^x

[Shift+X or h, e] Calculates 2 to the power of a value: 2¹⁰ is 1024. (Available when the 2nd button is clicked).

[p] Enters the value of PI or π (3.141592653589793…).

[h, p] Enters Euler's number e (2.718281828459045…), the base of the natural log. (Available when the 2nd button is clicked).

[Shift+W] An operator that multiplies the currently displayed value by 10 to the power of the next value you enter.

Ans

[a] Enters the last result, so it can be used anywhere in a new equation: 5 × Ans. It stays after C and AC.

Rand

[h, n or h, d] Returns a random number between 0 and 1.

[v] Click to clear the memory.

[b] Click to add the displayed number to the number in memory. If no number is in memory, click to store the displayed number in memory. The display shows M+ for a moment.

[n] Click to subtract the displayed number from the number in memory. If no number is in memory, click to store the displayed number as a subtraction of zero in memory. The display shows M– for a moment.

[m] Click to replace the displayed number with the number in memory.
An M on the display shows that a number is stored in memory. The M also disappears if the stored number calculates zero.

ⁿC_r

[Shift+N] Combinations: the ways to choose r of n things. For example 10 nCr 3 = returns 120. It works out before × and ÷, and after powers.

ⁿP_r

[Shift+P] Permutations: the ways to arrange r of n things in order. For example 5 nPr 2 = returns 20.

mod

[Shift+M] On the 2nd layer of %. The remainder after dividing: 17 mod 5 = 2. It takes the sign of the second number (-7 mod 3 = 2), and works with decimals (7.5 mod 2 = 1.5).

gcd

[Shift+Q] On the 2nd layer of ⁿC_r. The greatest common divisor of two whole numbers: 12 gcd 18 = 6.

lcm

[Shift+K] On the 2nd layer of ⁿP_r. The least common multiple of two whole numbers: 4 lcm 6 = 12.

abs

[|] The absolute value: the number without its sign. abs(-3) is 3.

round

[Shift+O] On the 2nd layer of Rand. The nearest whole number, half away from 0: round(2.5) is 3, round(-2.5) is -3.

floor

[Shift+Y] On the 2nd layer of abs. The whole number at or below: floor(2.7) is 2, floor(-2.7) is -3.

ceil

[Shift+U] On the 2nd layer of x!. The whole number at or above: ceil(2.1) is 3, ceil(-2.1) is -2.

About Precision

This calculator operates with a precision of about 15 significant digits (only). This is due to how JavaScript handles floating point numbers.
This isn't actually a JavaScript feature but a feature of the way the IEEE 754 standard defines how floating point numbers are stored in memory. JavaScript requires every number to be one of these 64-bit values, and any language that uses them, such as C, Java or Python, suffers from this 'feature' too.

Results are shown with 13 significant digits, so these tiny rounding errors stay out of sight: 0.1 + 0.2 shows 0.3, not 0.30000000000000004. Angles in degrees give exact values where they should: sin 180 is 0 and cos 60 is 0.5.

The problem is that JavaScript uses 64 bits of data, which can hold 18446744073709551616 different bit patterns, to store every number: 1 bit for the sign, 11 bits for the exponent and 52 bits for the digits. That covers values from about –1.7976931348623157e+308 to 1.7976931348623157e+308, with the smallest normal number at 2.2250738585072014e–308 and even smaller ones down to 5e–324.
A smaller precision value with some of the bits as an exponent is how it fits that range (this can also be done in 16 bits with a smaller range and less precision). The result is that it can approximate any value in the range but not exactly represent them all, because in real number terms there are an infinite number of values between any 2 given values.
As part of your calculation clearly the internal representation of the value is going outside the available precision and you are ending up with an approximation to the value instead of an exact value.