Triangle Calculator
Solve a triangle from three sides (SSS): get all angles, area, perimeter, heights and triangle type.
100% free No signup Private & offline-ready Works in your browser
About the Triangle Calculator
Enter the three side lengths of a triangle to find every angle (law of cosines), the area (Heron's formula), perimeter, height and whether it is equilateral, isosceles or scalene and acute, right or obtuse.
Frequently asked questions
Is the Triangle Calculator free?
Yes. The Triangle Calculator on Apex Tool Station is 100% free with no signup and no watermark. Browser tools have no usage limits.
Are my files or data uploaded to a server?
No. Everything runs locally in your browser using JavaScript. Your files and text never leave your device, which makes it safe for private documents.
Does it work on mobile?
Yes. The tool works on any modern browser on Android, iPhone, Windows, Mac and Linux.