Miter Angle Calculator
Perfect corners without guesswork. Enter the number of sides and the tilt of the piece to get the miter and bevel angles, plus a quick chart for common frames.
Workshop AI assistant
Describe the piece you want to build and get a complete plan: dimensions, cut list, materials, cost, steps, tools and time.
Workshop assistant
Describe the piece you want to build and get a complete plan: dimensions, cut list, materials, cost, steps, tools and time.
AI-generated results are indicative. Verify dimensions, loads and local codes before building.
How it works
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1
Enter the number of sides of your piece (4 for a picture frame, 6 for a hexagon…).
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2
Set the tilt angle: 0 for flat pieces, or the spring angle for crown molding.
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3
Calculate: the corner angle, the miter angle and the bevel angle are computed.
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4
A table shows the angles for common frame sizes with the same tilt.
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5
Cut on a scrap piece first to confirm your saw's reference.
Formula
Corner angle = 360° / n. Miter = atan( tan(corner/2) × cos(tilt) ). Bevel = asin( sin(corner/2) × sin(tilt) ). For flat pieces (tilt = 0): miter = corner/2 and bevel = 0. Angles are in degrees; verify against your saw's reference plane.
Practical tips
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Mark the outside face of each piece so the miter always meets at the same corner.
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For crown molding, test on offcuts — the saw reference changes how angles are read.
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Short pieces are easier to cut safely with a block or sled.
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Sanding a miter slightly undercuts it: a hair short is better than long.
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Use a stop block to cut identical sides.
Common mistakes
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Forgetting that the saw reads the angle from a different reference plane.
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Cutting all miters the same direction — alternate them for a frame.
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Ignoring the tilt for crown molding and cutting a flat miter.
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Trimming a miter after assembly, losing the corner.
Disclaimer
These results are indicative only. Always verify against local building codes, standards and professional advice before building.
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CalculateRelated guides
- How to Build a Wooden Table A complete beginner-to-intermediate walkthrough: design, cut, assemble and finish a dining table.
- Woodworking Joinery Guide From butt joints to dovetails: the strength, tools and uses of common joints.
- Cutting Miters and Compound Angles The trigonometry of perfect corners: miter and bevel formulas for frames, boxes and crown molding.