Compound Miter Calculator

Summary

Enter the spring angle and corner angle to get the exact blade tilt and miter angle for your compound miter saw.

How it works

1. Enter the spring angle — the angle at which the crown molding sits against the wall (typically 38° or 45°).
2. Enter the corner angle — the angle of the wall corner you are fitting (90° for a standard room corner).
3. The calculator derives the flat miter half-angle from the corner angle.
4. It applies the compound miter formulas to compute the saw blade tilt and horizontal miter angle.
5. Read the two saw settings and transfer them directly to your compound miter saw.

Use cases

• Installing crown molding around a standard 90° room corner.
• Fitting crown molding on non-square corners such as bay windows or vaulted ceilings.
• Cutting decorative casing or cornice molding at compound angles.
• Verifying saw settings before making expensive cuts on hardwood crown.
• Teaching students how spring angle affects compound cut geometry.
• Calculating settings for any angled joint where the workpiece sits at a tilt.

Frequently Asked Questions