Click the buttons or just type on your keyboard. The top line shows your expression and the big line shows the running result as you go. Press = or Enter to finish a calculation and add it to the history.
What keyboard shortcuts are there?
Digits 0-9 and . + - * / ^ % ( ) type directly.
Enter or = evaluates.
Backspace deletes the last character.
Esc clears everything (same as AC).
Can I keep calculating from a result?
Yes. After pressing =, typing an operator (like +) continues from the answer, while typing a new digit starts a fresh calculation. Click any line in the history to load that result back in.
Scientific functions
What functions are supported?
Tap Scientific to reveal sin, cos, tan, ln (natural log), log (base 10), sqrt (√), powers (^), factorial (!), and the constants π and e. You can nest parentheses freely, and 2(3+4) is understood as 2×(3+4).
DEG or RAD — what's the difference?
It sets how angles are interpreted for the trig functions. DEG treats sin(90) as 90 degrees (= 1); RAD treats the input as radians. Switch modes with the toggle above the keypad.
How precise are the results?
Calculations use standard double-precision floating-point maths, the same as most calculators and programming languages. Results are rounded for display, and very large or very small numbers switch to scientific notation (e.g. 1.23e+18).
Privacy & reliability
Is my input sent anywhere?
No. Expressions are parsed and evaluated entirely in your browser by a small built-in math parser — importantly, not the JavaScript eval() function — so it's both private and safe. Nothing is uploaded or stored, and the history clears when you refresh.
Does it work offline?
Yes — once the page has loaded it runs completely on your device.
