Online Calculator
Type the whole sum, functions and all, and read it as you go.
Runs entirely in your browser
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20
Tap the keys or type into the box, whichever suits. = puts the answer back in the box so the next sum can carry on from it. Functions: sqrt cbrt abs ln log log2 exp sin cos tan asin acos atan sinh cosh tanh floor ceil round sign fact. Constants: pi, e
Type the whole expression rather than pressing one button at a time:
(1200 * 1.07^5) / 12 evaluates exactly as written, with correct operator
precedence and right-associative powers. Functions include sqrt, ln, log, exp, the
trig family with a degrees/radians switch, floor, ceil, round and factorial, plus the
constants pi and e.
There is a keypad too, for a phone or a touchscreen or simply when clicking is easier than reaching for the keyboard. It types into the same box, so you can tap a few digits, type a function name, and tap the rest. The equals key puts the answer back into the box, which is how a calculator with one line lets the next sum carry on from the last one.
The three calculations people look up by name have pages of their own, because each is a different question rather than a mode of this one: the percentage calculator, the loan payment calculator and the BMI calculator.
How to use it
- Type an expression, or tap it out on the keypad. The result appears as you go.
- Switch between degrees and radians for trigonometry.
- Press = to put the answer back in the box and carry on from it.
Questions
How is -2^2 evaluated?
As -4. The power binds tighter than the leading minus, which matches mathematical convention and most calculators. Write (-2)^2 if you want 4.
What does % do here?
Modulo, the remainder after division, so 10 % 3 is 1. It is not a percent sign here, which surprises people often enough to be worth saying. For percentage arithmetic there is a separate page.
What is 2^3^2 here?
512. Powers are right-associative, so it reads as 2^(3^2), which is 2^9. Most programming languages and most scientific calculators agree; spreadsheets are the notable exception, where Excel evaluates it left to right and gives 64. If it matters, use parentheses and stop thinking about it.
How do I calculate a percentage increase?
Subtract the old value from the new one, divide by the old one, multiply by 100: (120 - 100) / 100 * 100 is a 20% rise. The percentage calculator does it directly, along with the three other questions people mean by the word.
Why does tan(90) give an enormous number instead of an error?
Because 90 degrees converted to radians is not exactly pi/2 in floating point, only extremely close, so the tangent is very large rather than undefined. Every calculator working in binary floating point does this. It is a good reminder that a result with sixteen digits is not the same as a result that is exact.
What binds first
| Level | What | Note |
|---|---|---|
| 1 | Parentheses and function calls | Innermost first |
| 2 | ^ | Right-associative, so 2^3^2 is 512, not 64 |
| 3 | Unary minus | Which is why -2^2 is -4 |
| 4 | * / % | Left to right |
| 5 | + - | Left to right |
Functions and constants it knows
| Group | Names |
|---|---|
| Roots and powers | sqrt cbrt exp |
| Logarithms | ln log10 log2 |
| Trigonometry | sin cos tan asin acos atan |
| Hyperbolic | sinh cosh tanh |
| Rounding | floor ceil round abs sign |
| Other | fact mod |
| Constants | pi tau e |
The trigonometric functions follow the degrees and radians switch, so
sin(90) is 1 in degrees and about 0.894 in radians. tau is
two pi, which makes a full turn tau radians rather than
2*pi.
Your data stays on your device
Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. You can load this page once, go offline, and it still works.
This page makes no requests at all, to anywhere. That is not a promise in the copy: it is a Content-Security-Policy header your browser enforces, and connect-src on it is none. Open the network tab and watch nothing happen.