Crown Molding Calculator - Calculate Linear Feet & Miter Angles

Free crown molding calculator for perfect installations. Calculate linear feet, miter angles, and material needed for crown molding projects. Determine cutting angles, material quantities, and project costs. Includes angle charts and installation tips. Perfect crown molding every time!

Miter Angles Material List Cutting Guide Installation

Room & Molding Specifications

Room Configuration

Room Dimensions

Room Length

Room Width

Ceiling Height

Number of Corners

Crown Molding Specifications

Molding Width

Molding Height

Spring Angle

Molding Style

Installation Parameters

Standard Length

Waste Percentage

Material Cost

Installation Type

Installation Analysis

Enter room dimensions and crown molding specifications to calculate material requirements, cutting angles, and installation measurements for your project.

Safety: Use proper safety equipment. Verify measurements twice before cutting. Use ladder safety at height.

Disclaimer: Calculations are installation guides. Test cuts on scrap. Angles depend on spring angle and corner configuration.

Professional Crown Molding Installation Guide

Crown molding installation requires precise compound miter calculations and professional cutting techniques. This guide covers spring angles, compound cut formulas, material estimation, and installation methods for professional results. Use our crown molding calculator for accurate angle calculations and material requirements.

Compound Angle Calculations

Spring Angle Basics

Spring Angle: The angle at which crown molding sits against the wall/ceiling. Most common are 38° and 45°.

Spring Angle	Miter Angle	Bevel Angle	Usage
38° Spring	31.6°	33.9°	Most Common
45° Spring	35.3°	30°	Traditional
52/38 Ratio	31.6°	33.9°	Contemporary

Note: These angles are for 90° corners. Non-90° corners require adjusted calculations. Always test cuts on scrap material.

Inside vs. Outside Corners

Inside Corners: Same angles, pieces meet in cavity
Outside Corners: Same angles, flip miter direction
Left vs. Right: Flip orientation, not angles

Non-90° Corners

Formula: For corner angle C: Miter = C ÷ 2, then adjust for spring angle using compound miter charts.

Installation Techniques & Material Estimation

Material Calculation

Formula: Linear Footage = Room Perimeter × 1.15 (15% waste)

Standard lengths: 8', 12', 16'
Optimize cuts to minimize waste
Add 10-15% for corners and mistakes

Cutting Methods

Nested Method (Recommended):

Lay molding upside down against saw fence
Bottom edge against fence, top edge on table
Cut at compound angles (both miter and bevel)
More intuitive, matches actual orientation

Flat Method (Alternative):

Lay molding flat on saw table
Requires compound miter saw capability
Use calculated miter and bevel angles

Professional Installation Tips:

Test Cuts: Always test compound angles on scrap first
Coping: Cope inside corners for better fit (cut along profile)
Backing Blocks: Add support at long spans (>6')
Nail Pattern: Into studs/joists every 16-24"
Caulk Gaps: Fill small gaps with paintable caulk

For related trim calculations, see our miter calculator and measurement tools.

Frequently Asked Questions

Spring angle is the angle at which crown molding sits against the wall and ceiling. Most crown molding has a 38° or 45° spring angle. This angle determines the miter and bevel angles needed for proper corner joints.

Crown molding is measured by its width (wall contact) and height (ceiling contact). The actual face width is larger. Always measure the flat surfaces that contact the wall and ceiling, not the decorative face.

For 90° corners with 38° spring angle: Inside corners use 31.6° miter and 33.9° bevel. Outside corners use 31.6° miter and 33.9° bevel but with opposite orientations. Always test cut on scrap material first.

Order 10-15% extra material for waste, mistakes, and future repairs. Complex rooms with many corners may need 20% extra. It's better to have too much than to run short and not match the profile later.

Yes, but it requires careful scribing and possibly flexible molding. Small irregularities can be handled with caulk. Large variations may require shimming or using flexible crown molding designed for uneven surfaces.

Essential tools include: compound miter saw, nail gun or hammer, level, measuring tape, pencil, safety glasses, and ladder. A crown molding jig for your miter saw makes cutting much easier and more accurate.