Polygon Calculator
Calculate the perimeter, area, and interior angle of a regular polygon (all sides and angles equal) from its number of sides and side length.
- Free to use
- Accurate results
- No registration required
- Works on all devices
Enter the number of sides and side length of a regular polygon to calculate its perimeter, area, and interior angle.
Your result
41.569
Area
Perimeter24
Interior angle120
Sum of all interior angles720
AI explanation
Formula
Perimeter = n × s; Area = (n × s²) / (4 × tan(π/n)); Interior angle = (n − 2) × 180 / nWorked example
Regular hexagon with side 4
| Field | Value |
|---|---|
| Number of sides | 6 |
| Side length | 4 |
| Area | 41.5692 |
| Perimeter | 24 |
| Interior angle | 120 |
| Sum of all interior angles | 720 |
Assumptions
- Applies only to regular polygons — all sides equal length and all interior angles equal. Irregular polygons need each side/angle measured individually.
Frequently asked questions
What is a regular polygon?
It's a polygon where every side has the same length and every interior angle is the same measure — like an equilateral triangle, a square, or a regular hexagon.
How is the interior angle of a regular polygon calculated?
Interior angle = (n − 2) × 180° / n, where n is the number of sides. For example, a square (n=4) has interior angles of (4−2)×180/4 = 90°.
What about a triangle, square, or circle specifically?
For a triangle from its sides, use the Triangle Calculator; for a square, use the Square Area Calculator; for a circle, use the Circle Calculator — each gives a more tailored result for that specific shape.