Pythagorean Theorem Calculator

Enter any two sides of a right triangle and leave one blank to solve it. Uses a² + b² = c².

Leave exactly one field blank. Here, c is the hypotenuse.
Result will appear here.
Metric Value

Uses a² + b² = c². Side lengths must be non-negative.

Privacy: calculations run locally in your browser. No values are stored or transmitted.

How it works

If c is missing: c = √(a² + b²)
If a is missing: a = √(c² − b²)
If b is missing: b = √(c² − a²)

Examples

  • a=3, b=4c=5
  • a=5, c=13b=12
  • b=8, c=17a=15

FAQ

  • What is the Pythagorean theorem?

    For a right triangle, a² + b² = c², where c is the hypotenuse.

  • Which value should be the hypotenuse?

    The hypotenuse is the longest side and is opposite the right angle. In this calculator, c is always the hypotenuse.

  • Can I leave one side blank?

    Yes. Leave exactly one of a, b, or c blank and the calculator will solve for it.

  • What if c is smaller than a or b?

    That would be invalid for a right triangle. The calculator checks for impossible values.

  • Are my inputs stored?

    No. Calculations run locally in your browser and are not stored or transmitted.

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