Overview
What Is a Triangle Calculator?
This tool calculates a triangle's area using base and height, and its perimeter using all three side lengths.
Calculate triangle area and perimeter instantly.
This tool calculates a triangle's area using base and height, and its perimeter using all three side lengths.
Useful for geometry homework and general triangle measurement problems.
Input these for area calculation.
Input these for perimeter calculation.
Area and perimeter update automatically.
Area = (Base × Height) ÷ 2, where height is perpendicular to the base.
Perimeter = Side A + Side B + Side C
No, this calculates area and perimeter from given measurements - angle-solving requires trigonometric methods.
You could use Heron's formula to find area from three sides alone, though this calculator uses base/height directly.
A valid triangle requires any two sides to sum to more than the third side - verify this holds for your measurements.
Yes, the area formula works for any triangle type including right triangles.
No, calculations happen entirely in your browser.
Use consistent units throughout (all inches, all cm, etc.) for a meaningful result.
Yes, decimal measurements are fully supported.
Yes, completely free with no sign-up required.