Pythagorean Theorem Calculator

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

Hypotenuse (c)
5cm
Area
6cm²
Perimeter
12cm
Angle at A
36.87°
Show the working
  1. 1c² = 3² + 4² = 25
  2. 2c = √25 = 5
Formula
a² + b² = c²

How it works

Relates the three sides of a right-angled triangle. Give any two and the third follows.

Example

With legs of 3 and 4, the hypotenuse is 5.

About the Pythagorean Theorem Calculator

Solve for any side of a right triangle with a² + b² = c². It sits in the Geometry section of NWS Calc, a free collection of calculators that run entirely in your browser. There is no signup, no paywall and no tracking — open the page, enter your numbers, get an answer.

Frequently asked questions

Is the Pythagorean Theorem Calculator free to use?
Yes. Every calculator on NWS Calc is completely free, with no signup, no usage limits and no ads.
Does my data leave my device?
No. The Pythagorean Theorem Calculator runs entirely in your browser using JavaScript. Nothing you type is uploaded, logged or stored on a server.
Can I use the Pythagorean Theorem Calculator on my phone?
Yes. The page is fully responsive and works in any modern mobile or desktop browser — there is nothing to install.
What else is in Geometry?
Area, perimeter, volume and surface area for every common shape. You can browse the full Geometry category for related calculators.

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