✓ Effortless Math · Free Tool

Heron's Formula Calculator

Find the area of a triangle from its three sides — with the semi-perimeter, perimeter, a height, the triangle type, a scaled diagram, and step-by-step working.

Area = √[ s(s − a)(s − b)(s − c) ],  s = (a + b + c)/2
side a side b side c

Enter the three side lengths. They must satisfy the triangle inequality (each side < the sum of the other two).

Results

Area (Heron's formula)
—
—
Semi-perimeter s
—
Perimeter
—
Height to side a
—
Type
—

Triangle diagram

TriangleVertices

Step-by-step