Pythagorean Theorem Calculator
Find the hypotenuse, or a missing side, of a right-angled triangle.
Your result will appear here as soon as you add some input.
How to use it
- 1Enter your values in the fields above.
- 2The answer and the working appear immediately below.
- 3Check the working to see the formula with your numbers substituted.
Formulas used
- a^2 + b^2 = c^2
About the Pythagorean Theorem Calculator
The theorem holds only for right-angled triangles, and the hypotenuse is always the longest side - the one opposite the right angle.
Reversed, it is also a test: if the squares of the two shorter sides add to the square of the longest, the triangle has a right angle. That is how builders square a corner with a 3-4-5 measurement.
Questions people ask
Is your figures uploaded to a server?
No. This tool runs entirely in your browser using standard web APIs, so your figures never leaves your device. You can confirm it by opening your browser's network panel while the tool runs, or by disconnecting from the internet after the page has loaded.
Is it free, and do I need an account?
Yes, it is free, and there is no account, no sign-up and no watermark on the result. The project is funded by optional donations.