How much trim do you actually need? This calculator figures out the linear feet of baseboard or crown molding for any room, subtracting door openings and adding waste for miter cuts so you can order confidently.
Room Dimensions
ft
ft
Doors & Board Size
ft
ft
Scenario: You're installing baseboard in a 16 ft x 10 ft guest room with 1 doorway (3 ft wide) using 8 ft baseboard pieces.
Result: Room perimeter is 52 ft. Subtract 1 doorway (3 ft) for 49 linear feet. With 10% waste that's 53.9 ft, so you need 7 baseboard pieces (each 8 ft long).
Measure the perimeter of the room (add all wall lengths together), then subtract about 3 feet for each doorway. Add 10% for waste from miter cuts at corners. For a 12x14 room with 2 doors, that's about 51 linear feet.
Baseboard comes in 8, 12, or 16-foot lengths. Divide your total linear feet by the length you're buying, then round up. Longer pieces mean fewer joints, which gives a cleaner look.
The waste factor covers corner cuts. Inside corners use a coped joint (one piece butts against the wall, the other is cut to fit the profile). Outside corners use miter cuts. Both create small offcuts that add to waste.
Baseboard covers the joint where the wall meets the floor. Crown molding covers the joint where the wall meets the ceiling. Both are measured the same way (linear feet around the room minus openings), but crown molding installation is more complex due to the angled cuts.
Want to learn more before you start your project?
Read the full guide →
All Calculators
