Crown molding angle calculator
Get the miter and bevel settings for crown molding laid flat on a compound miter saw, and the miter for a nested cut, from the corner angle and the spring angle. Each piece gets its fence edge, miter and bevel direction and the side to keep.
Corner angles from 10 to 179 degrees and spring angles from 1 to 89 degrees, measured from the wall or the ceiling. Angles are rounded to 0.01 degree. Calculated on your device; download a JSON report, a results CSV and a saw setup CSV. This calculator uses the measurement fields only. Results update as you type. Up to 1,000,000 characters.
Your result
How to use Crown molding angle calculator
- Choose an inside or outside corner and enter the angle between the two walls.
- Enter the spring angle and say whether it is measured from the wall or the ceiling.
- Read the flat miter and bevel, the nested miter and the setup for the left and right pieces.
- Make a test cut on scrap, then download the JSON report or the setup CSV.
Useful next steps
Angle conventions
Corner angle W is the angle between the two wall surfaces on the side where it is under 180 degrees: 90 for any square corner, inside or outside. Spring angle S is the angle between the wall and the back of the molding, from the edge touching the wall to the edge touching the ceiling: 38 for 52/38 crown, 45 for 45/45 crown. If your molding gives the angle from the ceiling, choose that option and it is converted to 90 − S.
Flat compound cuts
With the molding face up and its back on the table, miter = arctan(sin S ÷ tan(W ÷ 2)) and bevel = arcsin(cos S × cos(W ÷ 2)) (Wikipedia, Crown molding, Angle calculations, checked 16 October 2026). For a square corner and 38 degree spring this gives the familiar 31.62 degree miter and 33.86 degree bevel. We checked both formulas and every left, right, inside and outside setup against an independent three-dimensional vector derivation using right-triangle trigonometry (OpenStax Precalculus 2e, 5.4, checked 16 October 2026).
Saw directions
The miter is read from 0 for a square cut, and Right means the front of the blade swings to your right as you face the saw. The bevel is the blade tilt from vertical, and Left means the top of the blade tilts left, as on most single-bevel saws. If your saw tilts right, put the other edge of the molding on the fence and keep the piece on the other side of the blade, with the same miter.
Nested cuts and limits
Nested, the molding stands upside down with its ceiling edge on the table and its wall edge on the fence at its spring angle; then the miter is 90° − W ÷ 2 with no bevel. Left and right pieces are as seen facing the corner. Real spring angles and corners often differ from nominal, so cut scrap first, and expect warnings when a setting passes 50 degrees of miter or 45 of bevel.