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Crown molding miter and bevel calculator

Saw settings for trim and crown, any corner.

Open the Miter & Crown tool

Free. Runs in your browser, no account, and keeps working offline.

What it does

Crown molding sits at an angle between the wall and ceiling, so a compound miter saw needs two settings to cut it laid flat: a miter on the table and a bevel on the blade. This calculator gives both for any corner angle and the spring angle your crown is made in (38°, 45° or 52°).

If you cut crown nested — upside down against the fence at its spring angle — you only need a miter, and the calculator gives that too. Inside and outside corners use the same numbers; it shows which way to swing the saw and which piece to keep.

For trim that lies flat on the wall (baseboard, casing, chair rail) it gives the plain miter for any corner, and for closed frames and bay windows the cut for a given number of sides. Walls are rarely exactly 90°, so measure the corner first, with the Angle Finder or a bevel gauge.

Worked example

Standard 52/38 crown (38° spring angle) at a 90° inside corner, and again at a 135° bay corner.

90° corner, laid flat: miter / bevel
31.6° / 33.9°
90° corner, nested upside down: miter
45.0°
135° corner, laid flat: miter / bevel
14.3° / 17.6°
Flat trim (base, casing) at 92°: miter
44.0°

Inside and outside corners use the same numbers; the direction of the cut flips.

Try it with your numbers

Questions

What angle do I cut crown molding at for a 90° corner?

For common 52/38 crown laid flat: 31.6° miter and 33.9° bevel. Nested upside down at its spring angle: a 45.0° miter and no bevel.

What is the spring angle of crown molding?

The angle between the back of the crown and the wall when it is installed. Most crown is 38° (sold as 52/38) or 45° (45/45). Hold a speed square in the crown's back corner, or check the profile sheet from the supplier.

My corner isn't 90°. What do I change?

Measure the actual corner and enter it. Both the miter and the bevel change with the corner angle, which is why a 90° setting leaves a gap on an out-of-square wall.

Should I cut crown flat or nested?

Either works. Laid flat needs a saw that bevels; nested needs a fence tall enough to hold the crown at its spring angle. The calculator gives settings for both.

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