Triangle Area by Heron's Method Calculator

About this calculator

Heron's formula finds a triangle's area from its three side lengths alone, no angles or height needed: first the semi-perimeter s = (a + b + c) / 2, then Area = √(s(s−a)(s−b)(s−c)).

It's the go-to method whenever you can measure all three sides but can't easily drop a perpendicular height — surveyors computing irregular plots, carpenters checking a triangular panel, and students working land-survey or trigonometry problems all rely on it, and it works for any triangle shape, not just right triangles.