Pythagorean Theorem Calculator
Find any side of a right triangle — hypotenuse or either leg.
Formula: a² + b² = c²
The Pythagorean theorem
In a right-angled triangle, the square of the hypotenuse (c, the longest side opposite the right angle) equals the sum of the squares of the other two sides (legs a and b): a² + b² = c². Enter any two sides and the calculator finds the third using the appropriate rearrangement of this formula.
Frequently asked questions
What is a Pythagorean triple?
A Pythagorean triple is a set of three positive integers (a, b, c) satisfying a² + b² = c². The simplest is (3, 4, 5). Others include (5, 12, 13), (8, 15, 17), and (7, 24, 25). Any multiple of a triple is also a triple.
What are the units?
The calculator is unit-agnostic. If you enter sides in metres, the result is in metres. If you enter sides in feet, the result is in feet. Just be consistent.
