1. What does this tool do
This free formula calculator is built for typing math with your keyboard. Enter full expressions—arithmetic, trigonometry, logarithms, powers, combinations and permutations (ncr / npr), factorials, and constants pi and e—and evaluate them with one shortcut or click. It uses the same safe evaluation engine as the Scientific Calculator (deterministic parser, no eval()). Everything runs in your browser; nothing is sent to a server.
2. How to use it
Quick start: Type your expression, choose DEG or RAD for trig, then press Evaluate or Ctrl+Enter ( Cmd+Enter on Mac).
- Expression — Type in the box (e.g.
2+3*4,sin(90),5 ncr 2,sqrt(16)+ln(e)). Use Quick insert presets to addsin(),log(), nCr/nPr, or templates (hypotenuse, sphere volume, compound interest, quadratic root); the caret is placed where you most often edit. - Cheat sheet — Expand sections for operators, functions, constants, combinatorics, and tips (same syntax as the Scientific Calculator).
- Angle unit — For sin, cos, tan and inverse trig, pick degrees or radians.
- Evaluate — Click Evaluate or use Ctrl+Enter / Cmd+Enter. Missing closing parentheses are added automatically.
- Result — Copy the result or check Recent calculations for this session.
- Keypad — Prefer on-screen buttons? Open Scientific Calculator from the Math category on this site (same evaluation rules).
3. How it works
Expressions are tokenized, converted with a shunting-yard algorithm, and evaluated on a stack—the same pipeline as the Scientific Calculator. Multi-line input is supported: newlines and tabs are ignored like spaces. All processing is client-side.
4. Use cases & examples
- Long formulas — See and edit the whole expression at once.
- Keyboard-first workflow — No need to click calculator buttons.
- Homework and checks — Same rules as the scientific calculator for quick verification.
Examples
sin(90)(DEG) → 15 ncr 2→ 102*(3+4)→ 141.5e-10 * 2→ 3e-10