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.
Enter room dimensions and crown molding specifications to calculate material requirements, cutting angles, and installation measurements.
Spring Angle: The angle at which crown molding sits against the wall/ceiling. Most common are 38° and 45°.
Formula: For corner angle C: Miter = C ÷ 2, then adjust for spring angle using compound miter charts.
| 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 |
Linear Feet = Room Perimeter × (1 + Waste%) Formula: Linear Footage = Room Perimeter × 1.15 (15% waste). Standard lengths: 8', 12', 16'. Optimize cuts to minimize waste.
Nested Method (Recommended): Lay molding upside down against saw fence. Bottom edge against fence, top edge on table. 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.
A 12' × 10' rectangular room with 4 corners:
The angle at which crown molding rests against the wall/ceiling junction. Common values: 38° (most standard) and 45° (traditional). Determines the miter and bevel angles needed for proper corner joints.
A cut made at two angles simultaneously — miter (horizontal rotation) and bevel (blade tilt). Required for crown molding because it sits at an angle between wall and ceiling.
A technique where one piece of molding is cut to follow the profile of the adjoining piece. Creates tighter inside corners than mitering. Standard professional technique.
The horizontal angle at which the saw table rotates. For 90° corners with 38° spring angle: 31.6°. Set on the miter gauge or turntable of the saw.
The vertical angle at which the saw blade tilts. For 90° corners with 38° spring angle: 33.9°. Set on the bevel adjustment of the compound miter saw.
Positioning crown molding upside down against the saw fence, with the ceiling edge on the table and wall edge against the fence. Simplifies cutting by avoiding compound angle calculations.
A joint where two pieces of molding meet along a long wall. Cut at opposing 45° angles for a nearly invisible seam. Glue and nail for permanent bond.
Wood strips installed at the wall-ceiling junction to provide a nailing surface for crown molding. Essential when molding doesn't reach both studs and ceiling joists.
Spring angle is the angle at which crown molding sits against the wall and ceiling. Most has a 38° or 45° spring angle. This determines the miter and bevel angles needed for proper corner joints.
Crown molding is measured by its wall contact width and ceiling contact height. 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 the same angles but with opposite orientations. Always test cut on scrap first.
Order 10-15% extra for waste, mistakes, and future repairs. Complex rooms with many corners may need 20% extra. Better to have too much than run short and not match the profile.
Yes, but it requires careful scribing and possibly flexible molding. Small irregularities: caulk. Large variations: shimming or flexible crown molding for uneven surfaces.
Essential: compound miter saw, nail gun or hammer, level, measuring tape, pencil, safety glasses, and ladder. A crown molding jig makes cutting much easier and more accurate.