🔬 Scientific Calculator — Free, Offline, In-Browser
Get instant results for trig, logarithms, roots, and factorials — all inside your browser, completely free, with no data ever leaving your device. Switch between degree and radian mode, chain complex expressions, and review your full calculation history in one place.
About
Toolio's Scientific Calculator is a fully client-side expression evaluator built with a custom tokenizer and Shunting-Yard algorithm — no third-party math libraries, no server calls. It supports standard arithmetic, exponentiation, six trigonometric functions and their inverses, natural and base-10 logarithms, square root, absolute value, factorial (up to 170!), and the constants π and e. Because all computation happens locally in your browser, your calculations remain completely private and the tool works even without an internet connection.
How to use
- Type a number or tap a digit button to start building your expression.
- Select DEG or RAD to set the angle unit before using sin, cos, tan or their inverses.
- Use function buttons (sin, cos, ln, log, √, etc.) or type them with the keyboard — for example, press S for sin, L for ln, R for sqrt.
- Press = or Enter to evaluate. The result and full expression are saved to the history panel on the right.
- Click any history entry to recall that result and continue calculating from it.
FAQ
- Is this scientific calculator free to use?
- Yes, completely free. There is no account, subscription, or hidden fee — just open the page and start calculating.
- Does it work offline without an internet connection?
- Yes. All computation runs inside your browser using JavaScript. Once the page is loaded, you can disconnect from the internet and the calculator will continue to work.
- Is my data private? Are my calculations sent anywhere?
- No data is sent to any server. Every calculation happens locally in your browser, and your history is stored only in your browser's localStorage — never uploaded or shared.
- What functions and constants are supported?
- sin, cos, tan and their inverses (asin, acos, atan); natural log (ln) and base-10 log (log); square root (√); absolute value (abs); factorial (n!, up to 170); exponentiation (x^y, x²); the constants π and e; and standard arithmetic with parentheses.
- Can I use the keyboard to enter expressions?
- Yes. Type digits, operators (+, -, *, /, ^), and parentheses directly. Keyboard shortcuts: S → sin, C → cos, T → tan, L → ln, G → log, R or Q → sqrt, P or π key → π, E → e, Enter or = → evaluate, Backspace → delete, Escape → clear all.