What is the Pythagorean theorem?

In a right triangle, the square of the hypotenuse equals the sum of the squares of the legs: a² + b² = c².

How do I solve for the hypotenuse?

Leave c empty and enter a and b. The calculator returns c = √(a² + b²).

Leave the unknown leg (a or b) empty and enter the other leg and c. The calculator returns the leg = √(c² − other²).

The hypotenuse is always the longest side. If your input violates this, the calculator shows a clear error.

Yes — entirely in your browser.

a² + b² = c² — solve for any side of a right triangle.

100% private — no uploads Free & unlimited Read tutorial

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

Follow these steps — everything happens instantly in your browser.

Everything you might want to know about pythagorean theorem calculator.

Area (Heron's), perimeter and angles from three sides.

Area, circumference, diameter — and 90° arc & sector — from radius.

Solve ax² + bx + c = 0 — real and complex roots, with discriminant.

Range, max height, time of flight — for any launch angle and velocity.