NumberCals

Triangle Area Calculator

Calculate triangle area from base × height, or from three sides using Heron's formula.

About this calculator

The Triangle Area Calculator on NumberCals is a free, mobile-friendly tool for anyone needing to calculate triangle area from base × height, or from three sides using heron's formula. Enter your values in the form below and the result is computed instantly — no sign-up, no installation, no waiting.

Formula used

A = ½·b·h OR A = √(s(s−a)(s−b)(s−c))

What you'll need

  • Method
  • Base (or side a) (e.g. 10)
  • Height (for base × height) (e.g. 6)
  • Side b (Heron's only) (e.g. 7)
  • Side c (Heron's only) (e.g. 8)

What you'll get

  • Area
  • Perimeter (Heron's only)
Formula
A = ½·b·h OR A = √(s(s−a)(s−b)(s−c))

Frequently Asked Questions

Heron's formula vs base × height? +

Use base × height when you know one side and the perpendicular distance to the opposite vertex. Use Heron's when you only know the three side lengths.

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