Scientific Calculator

How this calculator works

Everything is evaluated in your browser — nothing is uploaded, and the page keeps working if you go offline. The engine is the same one that ships inside the SmartWot Android app, rewritten in plain JavaScript so the page loads instantly.

Basic and scientific modes

Basic mode covers the four operations, percentages and brackets. Switching to Scientific adds trigonometry (and its inverses), natural and base-10 logarithms, square and n-th roots, powers, factorials, and the constants π and e.

• DEG / RAD — trig functions respect the selected angle unit. In degree mode each call is converted individually, so a mixed expression like sin(30)+2 is not corrupted.
• Percentages — % is expanded to /100, so 200×10% gives 20.
• Backspace deletes a whole function name at once rather than leaving a half-typed si.

Two details most web calculators get wrong

tan at 90°. Because π cannot be represented exactly in binary, tan(90) evaluates to roughly 1.6 × 10¹⁶ instead of failing — a huge number presented as if it were correct. This calculator checks the angle you actually typed against tan's period and tells you the result is undefined.

Floating-point noise. 0.1 + 0.2 is 0.30000000000000004 in every IEEE-754 language. Results are trimmed so you see 0.3, while very large or very small values switch to exponential notation instead of overflowing the display.

Keyboard shortcuts

• 0–9 . + - * / ^ % ( ) ! type directly
• Enter or = evaluates
• Backspace deletes, Esc clears everything