Regular Polygon Area

A regular polygon area calculator computes area, perimeter, and circumradius for any regular polygon (equal sides and angles) given the side length and number of sides. Use this calculator for accurate, instant results.

The calculator uses the standard published formula for regular polygon area. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: Area = (n × s²) / (4 × tan(π/n)). Each step in the calculation is shown so you can verify the result manually.