- 38° Spring Angle (Standard): The profile rests at 38 degrees against the wall. Bevel: 33.9°, Miter: 31.6° for standard 90° corners.
- 45° Spring Angle: The profile rests at a 45-degree angle. Bevel: 30.0°, Miter: 35.3° for standard 90° corners.
- Upside Down & Backwards: If using nested cutting (bevel set to 0), place the crown molding on the saw bed upside down, with the ceiling edge flat on the saw table and the wall edge against the vertical fence.
- Test Scraps First: Always cut scrap test corners before cutting your expensive final molding trim boards to ensure settings match dry wall imperfections.
How to Cut Crown Molding: Flat vs Nested
Installing crown molding adds instant elegance and market value to any dining room, entryway, or bedroom. However, cutting crown corners is famously tricky. Because crown molding sits at an angle between the wall and ceiling (the spring angle), cutting it requires specialized calculations.
Our crown molding calculator provides the exact compound miter saw angles (horizontal miter and vertical bevel) needed to make your molding corners fit tightly together without unsightly gaps.
Wood trims respond to environmental factors, and dry walls are rarely straight. Drywall mud buildup at internal corners creates minor variations from the standard 90-degree angle. Using an angle finder to measure the true degree of the corner allows you to input precise values, avoiding the need to cover up wide gaps with caulk.
1. Compound Cutting (Flat) vs. Nested Cutting
There are two primary methods for cutting crown molding on a miter saw:
- Compound Cutting Flat (Standard): You lay the molding completely flat on the saw table. This is safer and easier to support for long crown boards, but requires adjusting both the saw miter angle and the blade tilt bevel angle simultaneously. Our calculator solves both angles instantly.
- Nested Cutting (Upside Down): You prop the molding at its spring angle against the miter saw fence. You only adjust the saw miter angle (no bevel adjustment needed), but you must flip the molding upside down and backwards, which can lead to mistakes.
If you choose nested cutting, remember that the ceiling side of the molding must rest flat on the horizontal saw table, and the wall side must rest against the vertical metal fence. This reverses the cut orientation, meaning left corners are cut as right angles and vice versa. Keep a reference guide close by to prevent layout errors.
2. Troubleshooting Uneven Wall Corners & Coped Joints
Drywall tape, metal corner beads, and framing settlement mean that very few inside or outside house corners are a perfect 90 degrees.
Before making cuts, measure the exact wall corner using a digital protractor or angle finder. If the corner is 88 degrees instead of 90, input 88° into our calculator. This small adjustment will prevent frustrating corner gaps during installation.
For high-end professional results on inside corners, consider **coping the joint**. Cut one molding board flush at a 90-degree angle against the wall, then make a compound miter cut on the second meeting board. Use a coping saw to cut along the profile edge of the miter cut, removing the back wood so it seats perfectly over the face of the first board. This accommodates drywall corner imperfections seamlessly.
Frequently Asked Questions
What is the spring angle of crown molding?▼
The spring angle is the angle at which the crown molding tilts forward when installed on the wall and ceiling. The most common spring angle is 38 degrees (often labeled 38/52 molding), but 45 degrees (45/45 molding) and 52 degrees are also widely used. You must know your molding's spring angle to compute the correct compound cuts.
How do you calculate miter and bevel settings for a 90 degree corner?▼
For standard 38-degree spring angle crown molding cutting flat on a saw bed: set your saw miter angle to 31.6 degrees and your bevel angle to 33.9 degrees. For 45-degree spring angle molding, set your miter to 35.3 degrees and your bevel to 30.0 degrees.
What is a compound miter cut?▼
A compound miter cut is a cut where the miter saw is rotated horizontally (miter angle) and tilted vertically (bevel angle) at the same time. This is required to make crown molding fit tightly together at corners when cutting the molding flat on the saw table.
Why are my miter cuts not fitting tightly at corner joints?▼
Most wall corners are rarely a perfect 90 degrees due to drywall buildup, mud layers, or framing settling. A corner might actually measure 88 or 91 degrees. You should measure your exact corner using an angle finder and input the precise degree value into our calculator to get customized saw settings.