Exterior Angle Calculator

About this calculator

For any convex regular polygon, the exterior angle at each vertex — the angle between one side and the extension of the adjacent side — is simply 360° divided by the number of sides (n), and the sum of all exterior angles always adds up to exactly 360° no matter how many sides the polygon has. The interior angle is just its supplement: 180° minus the exterior angle.

This relationship is one of the cleanest results in polygon geometry and a building block for more complex angle-chasing problems. Students and teachers use it to check work on interior/exterior angle problems, while drafters and CAD designers rely on it when laying out regular polygonal shapes, bolt-hole patterns, or architectural elements with equal-angle turns.