Pythagorean Theorem

Solve any side of a right triangle — a² + b² = c².

Calculator Numbers & Math Updated Apr 19, 2026
Sides
Result

Show Work

Enter values to see the step-by-step calculation.

Formula

Theorem
a² + b² = c²
Hypotenuse
c = √(a² + b²)
Leg
a = √(c² − b²)

About the Pythagorean Theorem

The Pythagorean Theorem is a simple, free helper for everyday maths and number work that runs entirely on your own device. Solve any side of a right triangle — a² + b² = c².

How it works

Enter your figures and the result appears instantly, updating the moment you change anything. There is no submit button and nothing to wait for, so it is easy to try a few what-if numbers and compare the results. Just check each box holds the kind of value it expects.

Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.

Frequently Asked Questions

How do I use the Pythagorean Theorem?

Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.

Does it cost anything or need an account?

No. The tool is completely free, there is no account to create, and it keeps working offline after the page first loads.

Is anything I type uploaded?

No. The tool works entirely on your device, so the values you enter never leave your browser.

Common Use Cases

Learn while you do it

Seeing what you put in and what comes out helps you understand how they fit together.

Get an answer fast

Type what you have and get the answer in seconds — on a phone, tablet, or computer.

Try different numbers

Change one thing and watch the answer change. It is an easy way to compare your choices.

Stays on your device

Your inputs never leave the browser — nothing is uploaded, logged, or stored anywhere.

Last updated: