How does percent work?

Percent divides by 100, so 50% becomes 0.5 and 200 × 15% equals 30. For “X plus Y%” you may want to compute Y% first.

Are angles in degrees or radians?

Trig functions use radians, matching JavaScript's Math library. To convert degrees, multiply by π/180 (e.g. sin(30 × π/180) for 30°).

Can I use the keyboard?

Yes. Digits, operators, parentheses, Enter (=), Esc (clear) and Backspace all work.

Is it safe to use Function() for evaluation?

The expression is sanitized to only allow digits, operators, parentheses, decimal points, the percent sign, and a known list of math function names. Anything else is rejected.

Why does my expression show an error?

Mismatched parentheses, unknown names, or invalid syntax will trigger a toast. Fix the expression and try again.

Scientific Calculator

A real working calculator: functions, constants, memory & percent.

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See how it works

Watch a quick simulation of this tool in action — no file needed.

How to use Scientific Calculator

Follow these steps — everything happens instantly in your browser.

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Step 1. Tap digit and operator buttons, or type directly on your keyboard.
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Step 2. Use sin/cos/tan/log/ln/√ and constants π and e for advanced expressions.
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Step 3. Memory keys (MC, MR, M+, M−) let you store intermediate values.
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Step 4. Press = or Enter to evaluate — the result becomes the start of the next calculation.