Pythagorean Theorem Calculator
a² + b² = c² where c is the hypotenusec=√(3²+4²)=√(9+16)=√25=5
Free online tool
Pythagorean Theorem Calculator
Enter the two known sides to find the unknown side using the Pythagorean theorem.
Instant calculation
Pythagorean Theorem Calculator
Enter the two known sides to find the unknown side using the Pythagorean theorem.
Your result
Calculation
Your numbers stay in this browser. Nothing is uploaded or saved.
Three clear steps
How to use this calculator
- 01
Enter side A
Type the length of one leg.
- 02
Enter side B
Type the length of the other leg.
- 03
See hypotenuse
Calculate to see the hypotenuse length.
The formula
How this calculation works
The square of the hypotenuse equals the sum of the squares of the other two sides.
Check the method
Worked examples
Each example follows the same formula used by the calculator.
Legs 3 and 4 — hypotenuse?
c=√(3²+4²)=√(9+16)=√25=55Common questions
Questions about this calculation
What is the Pythagorean Theorem Calculator?
The Pythagorean Theorem Calculator helps you find the hypotenuse or missing leg of a right triangle. Enter your values and select Calculate to get an instant result.
How is the result calculated?
The square of the hypotenuse equals the sum of the squares of the other two sides.
Can you show an example?
Example: Legs 3 and 4 — hypotenuse? — 5.
Is my data saved when I use the Pythagorean Theorem Calculator?
No. All calculations run locally in your browser. Your inputs and results are never uploaded, stored or shared with anyone.
Is the Pythagorean Theorem Calculator free to use?
Yes. The Pythagorean Theorem Calculator is completely free. No account, sign-up or payment is required. It works on mobile, tablet and desktop.
Continue calculating