Hypotenuse Calculator
Enter the two sides that meet at 90°. Find the diagonal in any supported unit.
Hypotenuse in every unit
How it is calculated
c = √(a² + b²)
Both sides are converted to meters first. Calculations use unrounded values; displayed results use up to 8 significant digits.
Find a circle’s diameter, circumference and area from its radius. Choose regional length units and see a labeled circle and conversion table.
Calculate triangle area from base and perpendicular height or from three side lengths. Mix regional units and follow the area formula with a diagram.
Add, subtract, multiply or divide fractions and mixed numbers. Follow exact fraction steps, simplification and a number-line diagram.
A little space to keep the tools free.
A few useful details
Does this work for any triangle?
This calculator is for right triangles only. The two entered sides must meet at 90°. The hypotenuse is the side opposite that right angle and is the longest side. For a rectangle, enter its width and height to find its diagonal.
Can I mix units, such as feet and inches?
Yes. Choose a unit independently for each side. For example, a = 3 feet and b = 48 inches gives c = 5 feet. The full conversion list shows that same hypotenuse in every supported unit. The page language does not limit your choice of units.
Why are there several kinds of 尺?
Regional and historical definitions differ. Here, Japan’s standard shaku (kanejaku) and Taiwan’s chi use 10/33 meter; mainland China’s modern shichi uses 1/3 meter; Hong Kong’s traditional chek uses 0.371475 meter. Japan’s cloth measure kujirajaku uses 25/66 meter and is listed separately. A ken here is 6 standard shaku. These named conventions do not represent every historical or local variation.
Which unit definitions are used?
Inches, feet, yards and miles use international length definitions, including exactly 0.3048 meter per foot. They do not use the old US survey foot. One international nautical mile is exactly 1,852 meters.
Are my measurements sent anywhere?
The calculation runs in your browser. It needs no account, file upload or external calculation API. Your language preference is remembered with a cookie when available.