Right Triangle Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter any two of: leg a, leg b, hypotenuse c.
- Read the remaining side, the angles, area and perimeter.
How it works
Pythagoras links the sides (a² + b² = c²); the angles come from the legs (tan A = a ÷ b), and area is ½ × a × b.
Worked example
Legs 3 and 4. Hypotenuse 5, angles 36.9° and 53.1°, area 6.
Common mistakes
- Entering the hypotenuse shorter than a leg — it must be the longest side.
- Using this for non-right triangles — it assumes a 90° angle between the legs.
Frequently asked questions
Which two values can I enter?
Any two of the two legs and the hypotenuse — the tool solves the rest. It assumes a right angle between the legs.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.