Free Online Calculator with Scientific Mode, Converter & Voice Input
A modern calculator built for everyday and advanced use. It runs entirely in your browser — no downloads, no sign-ups, and nothing is sent to a server. Switch between standard arithmetic, scientific functions, and a built-in unit and currency converter, all in one place.
Features
- Standard mode: addition, subtraction, multiplication, division, and percentages
- Scientific mode: sin, cos, tan, log, ln, square root, powers, π and e
- Voice input: speak a calculation instead of typing (e.g. "five plus three")
- Unit converter: length, weight, and temperature conversions
- Currency converter: live exchange rates with automatic offline fallback
- Dark and light themes: switch with a single tap
- One-tap copy: copy any result straight to your clipboard
- Calculation history: revisit anything you've calculated in this session
How to use voice input
Tap the microphone icon and clearly say your calculation, such as "twelve plus eight" or "fifty divided by five." The calculator converts your speech into an expression and fills the display automatically. Voice input works best in Chrome-based browsers.
Frequently asked questions
Are the currency rates live?
Yes, rates are fetched from a live exchange rate source when the page loads. If the connection fails, approximate fallback rates are used and clearly labeled.
Does voice input work on every browser?
It relies on your browser's built-in speech recognition, which is best supported in Chrome and Edge. If it isn't available, the calculator lets you know.
Is my data stored anywhere?
No. Everything — including history — stays in your browser tab and clears when you refresh or close the page.