Triangle Area Calculator
Area and perimeter from three side lengths.
How it works
Heron's formula: area = √(s(s−a)(s−b)(s−c)), where s is half the perimeter. If the sides cannot form a triangle, no result is shown.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.