Pythagorean Theorem Calculator
Find the missing side of a right triangle
Use this when you need a fast, accurate result — no sign-up, works entirely in your browser.
Missing side—
Triangle area—
How to Use
- Enter your details into the fields above.
- Click the calculate button to get your result instantly.
- Use the clear button to start a new calculation.
Example
- Legs a = 3 and b = 4 → Hypotenuse c = 5, triangle area = 6
- Leg b = 4 and hypotenuse c = 5 → Missing leg a = 3, triangle area = 6
Formula
a2 + b2 = c2, so c = √(a2 + b2) and a = √(c2 − b2). The right triangle area is (a × b) ÷ 2.
About Pythagorean Theorem Calculator
Find the missing side of a right triangle. This free online tool gives you fast, accurate results without registration or downloads.
Everything runs locally in your browser, so your data is never uploaded or stored — privacy first.
Frequently Asked Questions
Is this tool free to use? +
Yes, it is completely free with no registration or download required.
Is my data private? +
Yes. Everything is processed locally in your browser. Nothing is uploaded or stored on our servers.
Does it work on mobile? +
Yes, it works on any device — phone, tablet, or desktop.