Calculator

A basic and scientific calculator built with plain HTML, CSS and JavaScript — no build step, no dependencies.

Live: https://calculator-app-psi-tawny.vercel.app/

Features

• Basic mode: + − × ÷ with correct order of operations, %, ±, backspace
• Scientific mode: sin, cos, tan and their inverses (2nd), ln, log, eˣ, 10ˣ, x², x³, xʸ, √, ∛, x!, 1/x, |x|, mod, π, e, EE (×10ⁿ), parentheses and Ans
• Degrees or radians toggle
• Live preview of the answer while you type, with clear error messages
• Memory: MC, MR, M+, M−
• History of your last 50 calculations — tap one to reuse it
• Light and dark theme (follows your system, or toggle it)
• Keyboard support: digits, + - * / ^ ( ) ! %, Enter, Backspace, Esc, plus s sin, c cos, t tan, l ln, g log, r √, p π, e
• Works on phones, tablets and desktops (scientific keys sit beside the number pad on wide screens)

Expressions are evaluated with a small parser in script.js, never with eval.

Run locally

Open index.html in your browser.

Deploy

Every push to main on GitHub redeploys the site on Vercel automatically.