Triangle Calculator
Find a triangle's area from base and height, or from three sides.
Result
Results are estimates for general information only and are not professional advice.
Triangle area
The area of a triangle is ½ × base × height. If you only know the three side lengths, this calculator uses Heron's formula instead. Choose your method and enter the values.
Frequently Asked Questions
What is the Triangle Calculator?
Find a triangle's area from base and height, or from three sides. It runs instantly in your browser and is completely free to use.
What do I need to enter to use the Triangle Calculator?
The Triangle Calculator asks for the following values (4): Method, Base / side a, Height / side b, Side c (Heron only). Fill them in and the result appears immediately — the calculation runs on your own device, so nothing you type is sent to a server.
How accurate is the Triangle Calculator?
The Triangle Calculator uses standard, widely-accepted formulas, so its figures are reliable estimates for everyday planning. They are not a substitute for advice from a qualified professional.
Is the Triangle Calculator free, and do I need an account?
Yes. The Triangle Calculator — and every other calculator on Calculatis — is completely free, with no registration, no download and no limit on how often you use it.