Triangle Calculator
Calculate area, perimeter, angles and type from three sides (SSS)
Enter the lengths of all three sides:
Enter three side lengths to calculate triangle properties
About Triangle Calculator
This calculator uses the SSS (Side-Side-Side) method to determine all properties of a triangle. It uses Heron's formula for area: s = (a+b+c)/2, Area = √(s(s-a)(s-b)(s-c)). Angles are calculated using the Law of Cosines. The triangle type is classified by side equality and largest angle.
About this Calculator
The Triangle Calculator is a free, easy-to-use tool for area, perimeter, Pythagorean. Simply enter your values and get instant, accurate results — no signup, no ads, no tracking. All calculations run locally in your browser, so your data stays completely private.
Privacy Note: All calculations are performed locally in your browser. No data is ever sent to a server or third party.