Calculate the inradius (incircle radius) and other properties of a triangle's incircle. Enter side lengths.

Inradius: 1.6330
Area: 14.6969
Semi-perimeter: 9.0000
Circumradius: 3.6401
Incenter: (1.63, 1.63) (approximate)

Formula: r = Area / s, where s is the semi-perimeter. Area from Heron's formula.

Incircle of a Triangle

The incircle of a triangle is the circle that touches all three sides. Its radius r = Area / s, where s is the semi-perimeter .

How to Use This Calculator

1. Enter side lengths: a, b, c of the triangle.
2. Calculate: Click “Calculate” or press Enter.
3. Interpretation: Results show inradius, area, and circumradius.