Miter Angle Calculator

Calculate miter saw settings for regular polygon frames from the number of equal sides.

Author

Dr. Jean-Pierre Dupont

Woodworking editorial contributor

French cognitive psychologist at ENS Paris, investigating decision-making under uncertainty in financial markets

Reviewed by

Prof. Kenji Tanaka

Woodworking content reviewer

Japanese materials scientist at Kyoto University, known for breakthroughs in sustainable polymer research

Last updatedFebruary 22, 2026

PublishedFebruary 22, 2026

14-sided frame =

12.8571° miter

Representative value from the Miter Angle Calculator reference table.

Reference Values

Browse 22 reference values with individual detail pages for quick lookup.

Browse all reference values

Miter Angle Calculator

Enter the number of sides in a regular polygon frame to get miter and corner angles.

Miter Setting

Reference Table

Use this complete table for quick lookup and internal linking to specific value pages.

Miter Angle Calculator Reference
Frame TypeMiter AngleInterior AngleExterior Angle
3-sided frame60° miter60°120°
4-sided frame45° miter90°90°
5-sided frame36° miter108°72°
6-sided frame30° miter120°60°
7-sided frame25.7143° miter128.5714°51.4286°
8-sided frame22.5° miter135°45°
9-sided frame20° miter140°40°
10-sided frame18° miter144°36°
11-sided frame16.3636° miter147.2727°32.7273°
12-sided frame15° miter150°30°
13-sided frame13.8462° miter152.3077°27.6923°
14-sided frame12.8571° miter154.2857°25.7143°
15-sided frame12° miter156°24°
16-sided frame11.25° miter157.5°22.5°
17-sided frame10.5882° miter158.8235°21.1765°
18-sided frame10° miter160°20°
19-sided frame9.4737° miter161.0526°18.9474°
20-sided frame9° miter162°18°
21-sided frame8.5714° miter162.8571°17.1429°
22-sided frame8.1818° miter163.6364°16.3636°
23-sided frame7.8261° miter164.3478°15.6522°
24-sided frame7.5° miter165°15°

Frequently Asked Questions

Common questions about Miter Angle Calculator, formulas, and typical use cases.

How is miter angle calculated for a regular frame?

For an N-sided regular frame, miter angle = 180° / N, which is half of each exterior angle.

What is the difference between interior and miter angles?

Interior angle is the angle inside each corner; miter angle is the saw cut angle on each adjoining board end.

Can I use this for non-regular shapes?

No. This formula assumes all sides and corner angles are equal, as in regular polygons.

Why does a square use 45° miter cuts?

A square has four sides, so 180° ÷ 4 = 45° miter angle per piece end.

Methodology and Review

This page combines a live calculator, precomputed reference values, and FAQ content from the same conversion definition to reduce mismatch between calculator output and lookup tables.

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