Crown Molding Calculator

Crown Molding Calculator - Length and Miter Angle Estimator

Crown molding is sold by the linear foot but cut on an angle, which means simple room measurements understate what you actually need. This calculator converts your room dimensions into total linear feet of molding, with a waste allowance for miter cuts.

How to Use the Crown Molding Calculator

1. Room Length and Width: Enter both dimensions in feet
2. Molding Profile: Choose 3.5", 4.5", or 5.25" - larger profiles suit taller ceilings and larger rooms
3. Waste Percentage: 15% is a solid default for a room with standard square corners

Molding Profile and Installation Reference

Crown molding is milled with either a 38-degree or 52-degree spring angle (the two most common), and your miter saw settings need to match the profile's spring angle or the corners won't close cleanly. Inside corners are traditionally coped rather than mitered for a tighter, more forgiving joint, while outside corners are mitered. Add extra waste allowance beyond 15% for rooms with more than four corners, or for coped inside corners where you're sacrificing material to fine-tune the fit.

Crown molding is a popular way to dress up the top of a cabinet run - see our guide on adding crown molding to Shaker cabinets for cabinet-specific profile and installation guidance.

Related Tools

• Wainscoting Calculator - Another trim project for the same room
• Paint Calculator - Finish the room around your new molding
• Cabinet Pricing Estimator - Budget molding alongside your cabinets