How to Cut Polygon Angles in Wood – The Polygon Cutting Angle Cheat Sheet (Pentagon to Octagon)
If you’ve ever tried making a clean-looking wooden ring, frame, tray, planter, or decorative wall piece, you already know the secret is simple:
Perfect angles + consistent side lengths = tight joints.
http://1422woodworking.com/wp-content/uploads/2026/01/Polygon_Angle_Cheat_Sheet_Pentagon_to_Icosagon.pdf This cheat sheet gives you the most common regular polygon angle setups for woodworking projects—from a pentagon to an octagon—including the exact miter saw angle you’ll set for each shape.
If you learn best from videos, here is a video on how to find the proper angles to cut wooden polygons.
What These Angles Are (In Plain English)
When you build a regular polygon (all sides equal), each joint is made by cutting two matching angles that come together into one corner.
Here are the two angles you’ll hear about most:
- Interior Angle: the angle inside the shape at each corner (helpful for layout and understanding the geometry).
- Miter Saw Angle (per side): the angle you set on your miter saw to cut each piece so the joints close correctly.
Quick rule for regular polygons:
Miter Saw Angle = 180° ÷ Number of Sides
Pentagon (5 Sides) Cutting Angles
A pentagon is a great shape for small decor pieces and geometric wall art.
- Interior angle: 108°
- Miter saw angle: 36°
✅ Miter saw setting: 36°
Hexagon (6 Sides) Cutting Angles
Hexagons are super popular for shelves, trays, lantern-style projects, and modern wall art.
- Interior angle: 120°
- Miter saw angle: 30°
✅ Miter saw setting: 30°
Heptagon (7 Sides) Cutting Angles
Heptagons look awesome, but they’re less common because the angles are not as “clean.” Still totally doable—just do a test fit.
- Interior angle: ≈ 128.57°
- Miter saw angle: ≈ 25.71°
✅ Miter saw setting: 25.7° (round to the nearest tenth if your saw allows)
Octagon (8 Sides) Cutting Angles
Octagons are perfect for frames, signs, tables, and anything with that classic “stop sign” vibe.
- Interior angle: 135°
- Miter saw angle: 22.5°
✅ Miter saw setting: 22.5°
Quick Reference Table (Pentagon to Octagon)
Copy this table into your shop notes—or print it and hang it near your saw.
| Shape | Sides | Interior Angle | Miter Saw Angle (Per Side) |
|---|---|---|---|
| Pentagon | 5 | 108° | 36° |
| Hexagon | 6 | 120° | 30° |
| Heptagon | 7 | 128.57° | 25.71° |
| Octagon | 8 | 135° | 22.5° |
Woodworking Tips for Clean, Tight Joints
Here are a few small tricks that make a big difference when building polygon frames:
1) Cut test pieces first
Especially for a heptagon, small angle errors add up quickly. Cut scrap first and dry-fit the shape.
2) Use a stop block
If every side needs to be the same length (it does), a stop block is your best friend.
3) Dry fit with painter’s tape
Lay all pieces face down in a line, tape the seams, then fold it up into a ring. It’s fast, clean, and lets you check gaps before glue.
4) Clamp evenly
Band clamps work great for polygons. If you don’t have one, tape + careful pressure can still do the job.
