Right Triangle Calculator
Calculate the hypotenuse of a right triangle from its two legs, or the area of a triangle from its base and height. Free and private, right in your browser.
Hypotenuse (a² + b² = c²)
Triangle area
Enter any two known sides (or a side and an angle) of a right triangle and get the hypotenuse, missing leg, and area worked out instantly, handy for framing a rafter, sizing a ramp, checking a diagonal brace, or just double-checking geometry homework.
How to use it
- Enter any two known values, two sides, or a side and an angle
- Hit calculate to solve the missing side instantly
- Read off the hypotenuse, missing leg, and area
Frequently asked questions
- How do I find the hypotenuse without a calculator app?
- Enter the two leg lengths (a and b) and the tool applies the Pythagorean theorem, c = √(a² + b²), instantly. If you already have the hypotenuse and one leg, enter those instead and it solves for the missing leg.
- Can it find the area if I only know the hypotenuse?
- Yes. Give it the hypotenuse plus one leg (or one angle), and it derives the missing side first, then computes area as ½ × base × height using the two legs.
- What units does it use?
- None. It works in whatever unit you input (inches, cm, meters) and returns results in that same unit, squared for area. Keep your inputs consistent and the math stays correct.
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Nothing is uploaded
The file never leaves your device. There is no server to send it to, so there is nothing to leak, log, or subpoena.
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No signup, no limits
No account, no email, no daily cap, no watermark, and no paid tier waiting behind the third file.
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Works offline
Load the page once and it keeps working with the network off, because all the work was always happening locally.