Triangle Calculator

Calculate triangle area from base and height or from three sides.

Triangle Calculator helps you find area from base and height, or from three sides (Heron). Enter base, height, side a, side b, and side c, review the breakdown, and use the guidance below to understand what the number means — and what it does not. What the Triangle calculator does Triangle Calculator is built for arithmetic, algebra, geometry, and number tools. Find area from base and height, or from three sides (Heron). You enter base, height, side a, side b, and side c, then Simple Calculators computes the result instantly. Results use standard school and engineering formulas that run privately in your browser. How the math works Base-height area is bh/2. Heron’s formula uses s = (a+b+c)/2, then √(s(s−a)(s−b)(s−c)). The formula: A = √[s × (s − a) × (s − b) × (s − c)]. a, b and c are the sides; s = (a + b + c) ÷ 2 is half the perimeter. With base and height: A = (base × height) ÷ 2.