๐ Geometry
Triangle Area Calculator
With base and height, the area is simply half their product. With three sides, Heronโs formula uses the semi-perimeter to get the same answer without needing an angle.
How it works
Side a
Side b
Side c
Base (optional, overrides sides)
Height (optional, overrides sides)
Area
Perimeter
Semi-perimeter
Right triangle
Frequently asked questions
How do I use the Triangle Area Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.