15
About Math Expression Evaluator – Online Calculator
This math expression evaluator computes any arithmetic expression with the correct order of operations — multiplication and division before addition and subtraction, parentheses first, and right-associative exponentiation. Type something like `2 + 3 * 4` or `sqrt(16) + max(3, 7, 2)` and get the answer instantly.
Beyond the basic operators (+, −, ×, ÷, %, ^) it understands common functions — sqrt, sin, cos, tan, log, ln, abs, round, floor, ceil, min, max, and pow — plus the constants pi and e. It's a quick calculator for developers who want to evaluate a math expression without reaching for a REPL or spreadsheet.
The expression parser is hand-written and runs entirely in your browser. It never calls `eval`, never loads a heavy library, and never sends your input anywhere — so it stays fast, safe, and fully offline.
Features
- Correct operator precedence with parentheses and right-associative ^
- Built-in functions: sqrt, sin, cos, tan, log, ln, abs, round, floor, ceil, min, max, pow
- Constants pi and e; unary minus and scientific notation (1e3) supported
- Clear errors for bad syntax, unknown names, and division by zero — no eval, fully offline
How to use
- Type or paste a math expression into the input pane, e.g. (2 + 3) * 4.
- Read the result instantly in the output pane — the parsed expression is echoed in the status line.
- Copy the result, or clear the input and evaluate another expression.
Frequently asked questions
Does this use JavaScript eval?
No. The expression is parsed by a hand-written tokenizer and recursive-descent parser, then evaluated with safe math operations. Because it never calls eval, arbitrary code in the input can never run.
Which functions and constants are supported?
Functions: sqrt, sin, cos, tan, log (base 10), ln (natural log), abs, round, floor, ceil, min, max, and pow. Constants: pi and e. Trigonometric functions take radians, so sin(pi/2) is 1.
How is precedence handled?
Standard math precedence: parentheses first, then exponentiation (^, right-associative), then * / %, then + -. Exponentiation binds tighter than unary minus, so -3^2 evaluates as -(3^2), not (-3)^2 — use parentheses when in doubt.
What happens with invalid input?
Unknown identifiers or functions, mismatched parentheses, incomplete expressions, and division by zero all return a clear error message instead of a wrong answer or a crash.
Is my input sent to a server?
No. All parsing and evaluation happens locally in your browser. Your expressions never leave your device, so the tool works offline and keeps your data private.
Related tools
Everything runs locally in your browser — your input is never uploaded.