What is the spring angle on crown molding?

The spring angle is the angle the back of the crown sits at against the wall and ceiling. The two most common are 38 degrees and 45 degrees. It is often stamped on the back of the molding, and it changes your saw settings, so check it before you cut.

What miter and bevel do I set for crown molding on a 90 degree corner?

For a standard 38 degree spring crown on a square 90 degree corner cut lying flat on the saw, set the miter to about 31.6 degrees and the bevel to about 33.9 degrees. For 45 degree spring crown, both settings are about 35.3 degrees.

Why does my crown molding corner have a gap?

The most common causes are an out of square corner, a wrong spring angle, or letting the molding shift while cutting. Measure the actual corner angle, confirm the spring angle, and hold the stock firmly in the same position for every cut.

Can I cut crown molding lying flat?

Yes. Cutting it flat on the saw uses a compound cut with both a miter and a bevel setting, which is what this calculator gives you. The other method is cutting it nested upside down against the fence using only a miter, but flat cutting is more repeatable on wide crown.

AngleWise / Crown Molding

How to Cut Crown Molding:
Miter & Bevel Angles

Crown molding trips up more carpenters than anything else, because it sits at an angle to both the wall and the ceiling. Tell the calculator your spring angle and your corner, and it hands you the exact miter and bevel to dial into your saw — laying the crown flat, no guessing.

Crown Molding Calculator

Spring Angle — stamped on the molding; usually 38° or 45°

Wall Corner Angle — 90° for a square corner; measure it if unsure

The Terms, In Plain English

Spring Angle
The angle the back of the crown leans at between the wall and the ceiling. Almost always 38° or 45° — and it's often stamped on the back of the molding. Get this right first; it changes every other number.

Miter Angle
The setting you swing the saw table to, left or right. On a compound cut you set this and the bevel together.

Bevel Angle
The tilt of the saw blade away from vertical. Cutting crown flat on the table needs this tilt — that's what makes it a "compound" cut.

Corner Angle
The actual angle of the wall corner. A square corner is 90°, but real walls are often a degree or two off, which is why a cut that should be perfect sometimes leaves a gap.

How to Cut Crown Molding, Step by Step

Find your spring angle. Check the back of the molding or measure it. Set it in the calculator — 38° and 45° cover most crown sold today.
Measure your corner. Don't assume 90°. Hold a bevel gauge or angle finder into the corner. If it reads 89° or 91°, enter that — it's the difference between a tight joint and a visible gap.
Read your two settings. The calculator gives you the miter (table swing) and the bevel (blade tilt) for cutting the crown lying flat on the saw.
Set the saw and cut a test piece. Dial in both angles, lay a scrap flat, and cut. Hold it up to the corner before you touch your good stock.
Cut mirror images for inside corners. The two pieces meeting in a corner are cut as mirror images of each other — flip the setup, not just the board.

Flat vs. Nested: Two Ways to Cut Crown

There are two common methods, and it helps to know which one this calculator is for:

Flat (compound cut). Lay the crown flat on the saw table and use both a miter and a bevel. This is what the calculator gives you. It's repeatable and works well on wide crown that won't sit steady on edge.
Nested (upside down). Stand the crown against the fence upside down and backward, the way it sits on the wall, and use only a miter. Simpler for narrow crown, but harder to hold steady as the crown gets wider.

Common Mistakes

Assuming the corner is square. Most gaps come from a wall that's a degree or two off 90°. Measure it.
Wrong spring angle. Cutting 45° settings on 38° crown (or vice versa) throws both the miter and bevel off. Confirm it before the first cut.
Letting the stock shift. If the crown moves even slightly mid-cut, the joint won't close. Hold it firm and in the exact same position every time.
Not cutting a test piece. Crown is the one trim job where a quick scrap test saves expensive molding. Always do it.

Frequently Asked Questions

What is the spring angle on crown molding?: It's the angle the back of the crown sits at between the wall and ceiling — most often 38° or 45°, and usually stamped on the back. It changes your saw settings, so check it before you cut.
What miter and bevel do I set for a 90° corner?: For 38° spring crown on a square corner, cut flat: miter about 31.6° and bevel about 33.9°. For 45° spring crown, both are about 35.3°. The calculator above gives the exact numbers for your corner.
Why does my crown molding corner have a gap?: Usually an out-of-square corner, the wrong spring angle, or the stock shifting during the cut. Measure the real corner angle, confirm the spring angle, and hold the piece firmly.
Can I cut crown molding lying flat?: Yes — that's the compound-cut method, using both a miter and a bevel, which is what this calculator provides. It's the more repeatable way on wider crown.

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