Crown Molding Calculator

Crown molding prices vary significantly by material, size, and profile complexity:

Material Costs (Per Linear Foot):

Installation Labor (2026):

Total Installed Costs by Room Size:

Costs assume standard 3.5-5" painted MDF crown. Premium materials increase significantly.

The spring angle determines how crown molding sits between wall and ceiling—using the wrong angle makes all cuts incorrect:

What is a Spring Angle? The spring angle is the angle between the back of the crown molding and the wall when installed. It determines how far the molding projects from the wall and ceiling junction.

Common Spring Angles:

How to Identify Your Molding's Spring Angle:

Method 1 - Manufacturer Specs:

• Check the label or product listing
• Most standard crown is 52/38
• Decorative/period crown may differ

Method 2 - Framing Square Test:

1. Hold molding against a framing square
2. Position as it would sit on wall/ceiling
3. Measure angle between back and square edge

Method 3 - Spring Angle Gauge:

• Commercial gauges available ($10-20)
• Most accurate method
• Worth buying for multiple rooms

Why Spring Angle Matters: Using 45° calculations on 38° molding (or vice versa) produces cuts that:

• Gap at the front (visible side)
• Gap at the back (less visible but structurally weak)
• Require excessive caulking to hide
• Never fit properly regardless of adjustments

Pre-calculated angles for common corner and spring angle combinations:

90° Corners (Standard Rooms):

135° Corners (Bay Windows, Octagon Rooms):

120° Corners (Hexagon Bays):

Out-of-Square Corners (Adjustments):

For non-standard angles, use this calculator for precise settings.

Inside and outside corners require different cutting approaches and saw orientations:

Inside Corners (Concave - Most Common): Inside corners are where two walls meet and form an inward angle—the standard corners in every room.

Cutting Method for Inside Corners:

Outside Corners (Convex): Outside corners project outward, like around a fireplace bump-out, soffit, or kitchen soffit.

Cutting Method for Outside Corners:

Note: Outside corners are the opposite of inside corners.

The Coping Alternative (Inside Corners Only): Professional finish carpenters often cope inside corners for better results:

1. First piece: Cut square (90°) and install tight to corner
2. Second piece: Cut compound miter as calculated
3. Coping cut: Use coping saw to cut along the profile edge, removing waste
4. Install: Coped piece overlaps square-cut piece, front edges meet tightly

Why Cope Inside Corners?

The nested method positions crown at its spring angle against the saw fence, eliminating bevel cuts entirely:

How It Works: Instead of laying the crown flat and making compound cuts, position the crown upside-down against the fence at its installed angle. The fence represents the ceiling, the table represents the wall.

Setup for 90° Corners:

Advantages of Nested Method:

• No complex compound angle calculations
• Angles are "built in" to positioning
• Works on any miter saw (no bevel needed)
• Faster for standard 90° corners
• Less math, fewer errors

Disadvantages:

• Requires tall fence (limits molding size)
• Difficult with large crown (6"+)
• Only works for standard spring angles
• Non-90° corners still need calculations
• Positioning must be consistent

Spring Angle Positioning:

Making a Crown Stop:

1. Cut a triangular block matching your crown's spring angle
2. Attach to fence with clamps or screws
3. Crown back rests against block
4. Ensures consistent positioning for every cut

Many homes have corners that aren't exactly 90°—accurate measurement is essential:

Common Non-90° Situations:

Measuring Corner Angles:

Digital Angle Finder (Most Accurate):

1. Place one arm against each wall
2. Read the digital display
3. Accuracy: ±0.1°
4. Cost: $25-80

Adjustable Bevel Gauge:

1. Set gauge to match corner
2. Transfer to protractor
3. Accuracy: ±1°
4. Cost: $10-25

Two-Board Method:

1. Hold straight boards against each wall
2. Mark where they cross
3. Measure with protractor
4. Accuracy: ±2°

Calculating Odd Angles: This calculator handles any corner angle. For manual calculation:

Miter = arctan(sin(spring) / tan(corner/2))
Bevel = arcsin(cos(spring) × cos(corner/2))

Example: 135° Bay Window Corner (38° spring):

• Corner half-angle: 135° ÷ 2 = 67.5°
• Miter: arctan(sin(38°) / tan(67.5°)) = 14.2°
• Bevel: arcsin(cos(38°) × cos(67.5°)) = 17.7°

Much different from 90° settings of 31.6°/33.9°!

Choosing the right crown molding material affects appearance, workability, and longevity:

MDF (Medium-Density Fiberboard):

Best for: Budget projects, paint-grade finish, dry rooms

Finger-Joint Pine:

Best for: Paint-grade, straightforward installation

Solid Wood (Pine, Poplar):

Best for: Traditional homes, paint or stain finish

Hardwood (Oak, Cherry, Maple):

Best for: Formal rooms, stain finish, visible grain desired

Polyurethane/Foam:

Best for: DIY projects, bathrooms, difficult installations

Crown size should be proportional to ceiling height and room scale:

Size by Ceiling Height:

Room Size Considerations:

Profile Complexity:

Visual Tricks:

• Large crown makes ceilings feel lower (cozy)
• Small crown makes rooms feel taller (spacious)
• Detailed profiles add formality
• Simple profiles suit casual spaces

Multi-Piece Crown: For dramatic effect, combine multiple moldings:

Professional installation techniques ensure tight joints and lasting results:

Before You Start:

• Acclimate molding to room temperature/humidity (24-48 hours)
• Prime and paint before installation (touch up after)
• Mark stud locations on walls (or plan for adhesive)
• Number pieces and plan cutting sequence

Essential Tools:

Installation Sequence:

1. Mark reference line (ceiling or wall, depending on installation)
2. Start with longest wall (minimizes visible joints)
3. Work around room in one direction
4. Install inside corners first (coped pieces)
5. Fit outside corners last (can adjust length)
6. Fill nail holes, caulk gaps, touch up paint

Nailing Pattern:

Common Problems and Solutions: