Triangle Area (Heron's Formula)
Calculate triangle area (heron's formula) using Side a, Side b, Side c, Semi-perimeter. See the method, result interpretation, practical checks and related calculators in one place.
Formula / method
s=(a+b+c)/2; area=√(s(s−a)(s−b)(s−c))
How to use
Use dimensions from the same unit system and identify whether values are radius, diameter, height, side length or slant height.
What this calculator answers
The Triangle Area (Heron's Formula) uses Side a, Side b, Side c, Semi-perimeter to calculate the requested result. The core method is s=(a+b+c)/2; area=√(s(s−a)(s−b)(s−c)). This makes the assumptions visible so you can check whether the inputs match your situation.
How to get a useful result
Use dimensions from the same unit system and identify whether values are radius, diameter, height, side length or slant height.
How to interpret it
Geometric results assume the ideal shape described by the formula; real objects may require tolerances or waste allowances.
Before relying on the number
Recheck unusual inputs, confirm units and compare the result with any official quote, statement, specification or rule that applies to the real decision. Small changes in rates, time periods or measurements can materially change some results.