Pythagorean Theorem Calculator

Free online Pythagorean theorem calculator with step-by-step solutions. Calculate the length of any side of a right triangle instantly.

a² + b² = c²

Side A (a)

units

Leg of triangle

Side B (b)

units

Leg of triangle

Hypotenuse (c)

units

Longest side (leave empty to calculate)

a=3, b=4 → c=?

c=5 (3-4-5 Triangle)

a=5, c=13 → b=?

b=12 (5-12-13 Triangle)

a=8, b=15 → c=?

c=17

b=9, c=15 → a=?

a=12