Crown molding angle calculator
Enter the wall corner angle, pick the crown's spring angle, and get the exact miter and bevel for your saw — as a compound miter calculator for crown lying flat, or a plain miter saw angle calculator for crown nested against the fence. Pricing the material run? Use the board foot calculator.
Odd corner? Measure it with an angle finder, or hold two overlapping test offcuts in the corner and read the angle between them — drywall corners routinely come out at 88–94°, and the cut follows the wall, not the blueprint.
31.62° / 33.86°
miter / bevel — turntable and blade tilt, crown lying flat
| Miter (turntable setting) | 31.62° |
| Bevel (blade tilt) | 33.86° |
| Corner bisect angle (per piece at the joint) | 45.00° |
Compound cut: the crown lies flat on the saw bed, so the saw combines the turntable (miter) and blade tilt (bevel) in one pass. Swing the turntable the opposite way for the mating piece — inside and outside corners use the same angles, mirrored.
Flat frames and segmented work
Picture frames, segmented rings, octagon trays: every joint of a regular frame takes the same miter — 180° divided by the number of sides, read straight off the saw's detent scale.
Set the saw to 45.00° — the same cut at every joint.
How it works
Lying flat, the saw combines two rotations:miter = atan(sin(spring) ÷ tan(corner÷2)) andbevel = asin(cos(spring) × cos(corner÷2)). For the textbook 90° corner with 38° crown that gives the classic 31.62°/33.86° pair. Nested against the fence, the setup itself cancels the spring angle — the fence plays the wall, the bed plays the ceiling — so only the corner gets bisected: miter = 90° − corner÷2 on the saw's scale (45° for a square corner). Flat frames bisect the polygon instead:180° ÷ sides per joint.
Worked example: square corner, 38-degree crown
Standard US crown has a 38° spring angle. In a true 90° inside corner, cut lying flat, the compound miter calculator gives a 31.62° turntable setting and a 33.86° blade bevel — the 31.6/33.9 pairing many saws print next to their detents. Cut the same molding nested against the fence and it is one 45.00° miter per piece with the bevel locked at zero.
Real rooms are not square. Measure that corner with an angle finder and it commonly reads 92° — drywall mud fills the inside, framing twists as it dries. At 92° the flat settings move to a 30.73° miter and 33.19° bevel; nested, to 44.00° per piece. Two degrees of wall error shifts the cut by about a degree, enough to open a visible gap on a painted joint, which is why pros measure every corner instead of assuming 90. For inside corners that refuse to close, coping the second piece is the traditional fix.
The frame mode above handles picture frames and segmented rings: the per-joint miter is 180° divided by the number of sides, so a hexagon takes 30.00° at each joint. Budget the material run with the board foot calculator, keep bit RPM sane when running your own profiles with the router speed calculator, and find the rest of the shop math on the woodworking hub.
Frequently asked questions
What spring angle is my crown — 38°, 45° or 52°?
Most US crown molding is 38°, 45° is common on larger profiles, and 52° is the common European profile (often sold as 52/38). The spring angle is the tilt of the molding's back against the wall; check the packaging or measure the cut end with a protractor or angle finder, because every number on this page depends on it.
What are the miter and bevel settings for 38-degree crown on a 90-degree corner?
Cut lying flat: 31.62° miter and 33.86° bevel — the classic 31.6/33.9 settings printed on many miter saws. Cut nested against the fence instead and it is a single 45° miter with the bevel at 0°, the molding upside down and backwards.
Are inside and outside corners cut at the same angles?
Yes — the miter and bevel magnitudes are identical. Only the direction changes: swing the turntable the opposite way and cut the mating piece as a mirror image. An outside corner is the same geometry seen from the other side of the wall.
Should I cope inside corners instead of mitering them?
Coping is the traditional alternative for inside corners: the first piece runs square into the corner and the second is cut along its profile with a coping saw so it overlaps. A cope hides out-of-square walls and stays tight as the house moves, while a miter is faster to cut. Many pros cope every inside corner and miter only the outside ones.
Why is my wall corner not exactly 90 degrees?
Drywall compound builds up in inside corners, studs twist as they dry and old plaster rounds over — real rooms routinely measure 88–94°. Check each corner with an angle finder or two overlapping test cuts before touching the good stock; a 2° wall error shifts the per-piece miter by about a degree.