Scientific Calculator
An expression calculator that accepts real mathematical notation, with a running history.
Runs in your browserInput
Keypad
Good to know
- The mod key returns the remainder: 200 mod 10 is 0, not 20. There is no percent key because a single symbol cannot honestly mean both.
- Trigonometric functions work in radians. For degrees, write the conversion: sin(30 × pi / 180).
- Results are double-precision floating point, displayed to twelve significant digits so 0.1 + 0.2 reads as 0.3 rather than 0.30000000000000004.
About this tool
Type a whole expression and get the answer, instead of pressing one operation at a time. It understands operator precedence, brackets, powers, constants like pi, and the functions people actually reach for, and it accepts the shorthand you would write on paper such as 2x or 3(x+1). Everything is evaluated locally by a parser written for this purpose, not by handing your input to the browser to execute.
How to use it
- 1Type the expression, or use the keypad. Press Enter or the equals key to evaluate.
- 2Watch the live preview to check the result before you commit to it.
- 3Click any line in the history to bring that expression back and edit it.
Frequently asked questions
Why is the percent key labelled mod?
Because that is what the operator actually does: it returns the remainder, so 200 mod 10 is 0, not 20. Many pocket calculators overload the percent sign to mean something else, and copying that ambiguity into a text-based calculator produces answers people do not expect. It is labelled mod so the behaviour is unambiguous.
Do the trigonometric functions use degrees or radians?
Radians, which is the mathematical definition and what every programming language uses. If you need degrees, convert first by multiplying by pi and dividing by 180 — writing sin(30pi/180) rather than sin(30). The tool says this on the page too, because getting it wrong is silent: it returns a plausible-looking number that is simply not the one you wanted.
How precise is the arithmetic?
It uses the browser's double-precision floating point, the same as every other calculator, then rounds the displayed result to twelve significant digits. That is why the tool shows a clean 0.3 for 0.1 + 0.2 while a raw console would print 0.30000000000000004. For money or anything reconciling to the cent, round explicitly and check the rounding rule your context requires.