What is a spring angle?

The spring angle (also called the work angle) is the angle between the back face of the crown molding and the wall. Standard crown molding is commonly made at 38° or 45°. Check the molding packaging or measure the angle with a sliding bevel.

What blade tilt and miter angle do I use for standard 38° crown on a 90° corner?

For a 38° spring angle at a 90° corner, set the blade tilt to about 33.9° and the miter angle to about 31.6°. This calculator gives those numbers precisely.

What blade tilt and miter angle do I use for standard 45° crown on a 90° corner?

For a 45° spring angle at a 90° corner, set the blade tilt (bevel) to 30.0° and the miter angle to 35.26°. These are the standard flat-on-table settings for 45° crown.

Why do I need both a blade tilt and a miter angle?

Crown molding does not lie flat on the saw table — it sits at a spring angle. A flat cut would leave a gap. The blade tilt compensates for the vertical slope and the miter angle compensates for the horizontal corner, together producing a tight joint.

Can I cut crown molding flat on the saw table instead?

Yes — the alternative is to stand the molding upright against the fence at its spring angle and make a simple miter cut with zero blade tilt. This calculator covers the flat-on-table compound method, which is often easier for long pieces.

Is the result the same for inside and outside corners?

The angles are the same in magnitude. For outside corners you flip the miter direction (left vs. right). The blade tilt stays the same; only the fence side of the miter changes.

Compound Miter Calculator

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

Saw Input

Spring angle (°) — how molding sits against wall

Common values: 38° or 45°. Check molding spec or measure.

Corner angle (°) — room or wall corner

Standard square room = 90°. Bay windows often 135°.

Quick presets

Saw Settings

Blade Tilt

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Vertical saw tilt

Miter Angle

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Horizontal rotation

Common Crown Molding Reference

Spring	Corner	Blade tilt	Miter angle

Summary

This compound miter calculator works out the two saw settings you need when cutting crown molding or any workpiece that sits at an angle to the wall: blade tilt and miter angle. Enter the spring angle (how the molding sits against the wall) and the corner angle (the room corner you are fitting), and the tool returns both settings instantly using the standard compound miter trigonometry formulas.

How it works

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

Last updated: 2026-06-13 · Reviewed by Nham Vu