Math Expression Evaluator

How to use

1. Type an expression — operators, parentheses, decimals, and the allowed names.
2. The result updates live; copy it if you need to paste elsewhere.
3. `^` is exponent (like in math, not bitwise XOR). For powers of variables use `pow(x, y)` or `x^y`.

Frequently asked questions

Is `eval` being used under the hood?

A `new Function(...)` call is used, but only after the input is parsed for identifiers and matched against an allowlist (`sin`, `sqrt`, `pi`, …). Anything else — `document`, `window`, `fetch`, string literals, semicolons — is rejected before execution, so the expression has no way to reach outside `Math.*`.

What angle unit do `sin` and friends use?

Radians, matching JavaScript's `Math.sin`. Use `pi` to express common angles — `sin(pi / 2)` is 1, `cos(pi)` is -1. To convert degrees, multiply by `pi / 180` before passing in.

Why does my huge calculation lose precision?

JavaScript numbers are IEEE 754 doubles — about 15 significant decimal digits. `0.1 + 0.2` gives `0.30000000000000004`. For higher precision (financial decimals, factorials past 20!, etc.) use a dedicated arbitrary-precision tool or library.

What about variables or multi-line scripts?

Not supported on purpose — keeping the surface area small is what makes this safe to evaluate. For programmable math, use a Jupyter notebook or a desktop calculator.

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