Three calculators in one: X% of Y, X as a percentage of Y, and percentage change
Math Expression Evaluator
Runs locally
Use Math Expression Evaluator
What it does
Type an arithmetic expression and press Evaluate or Enter. It understands the basic operators, powers, remainders, parentheses and a short list of Math functions and constants.
It runs entirely in your browser: nothing you enter is uploaded.
Example
Area of a circle with radius 2
Math.PI * 2 ** 212.566370614359172Returns 12.566370614359172 (π × 2²); ** is applied before *.
FAQ
What can I type?
Numbers (including forms like 1e3), + - * / ** and % (remainder, not percent), parentheses, and functions written with the Math. prefix: Math.sin, cos, tan, sqrt, abs, floor, ceil, round, log (natural logarithm) and pow, plus Math.PI and Math.E. There are no variables, and angles are in radians.
Why is a result like 0.1 + 0.2 slightly off?
Results are JavaScript 64-bit floating-point numbers shown without rounding, so 0.1 + 0.2 gives 0.30000000000000004. Division by zero gives Infinity and Math.sqrt(-1) gives NaN.
Is the expression executed as code or sent anywhere?
No. A small parser in the page reads only the allowed syntax instead of using eval(), and the calculation runs in your browser without any upload.