Skip to content
Builders-Tools
My project listConcrete calculatorConcrete slab calculatorCubic yard calculatorSee all: Concrete and masonryRoofing calculatorRoof pitch calculatorStair calculatorSee all: Framing and roofingGravel calculatorMulch calculatorTopsoil calculatorSee all: Landscape and hardscapeBags of concrete per yardConcrete curing timeLumber size chartSee all: Guides

Baseboard and trim calculator

Enter the room and the doors.

Enter your numbers to see the result.

Trim is measured in linear feet around the room. Longer pieces mean fewer seams, but they have to fit in your vehicle.

How it works

  • Perimeter: 2 x (length + width).
  • Baseboard: perimeter minus the doorways. Crown: the full perimeter.
  • Add extra for miters and mistakes (10% is a common allowance; more if you are new to coping inside corners).
  • Pieces: total / piece length, rounded up. Each wall uses whole pieces where it can, so the count can be a little higher in a room with many short walls.

Door casing is about 17 ft per side of a standard 3 x 6 ft 8 in door (two legs and a head), so 34 ft per door if you trim both sides.

Frequently asked questions

How much baseboard for a 12 x 14 room?

The perimeter is 52 ft; minus two 3 ft doors is 46 ft, about 51 ft with 10% extra, or four 16 ft pieces.