How much baseboard do I need for a room?

Perimeter less the doorways, plus 10% for miters and mistakes — a 12x14 room takes four 16-foot sticks. The arithmetic, and lengths for every room size.

A 12' × 14' room takes 4 sticks of 16' baseboard.

46 ft 4 in of wall to cover once the doorways come out, 50 ft 11 5/8 in with 10% waste — so 4 sticks and 13 ft 3/8 in spare.

How that is worked out

  1. Perimeter first: (12' + 14') × 2 = 52' of wall.
  2. Take out the openings the trim does not cross — a 36" doorway and a 32" one here — leaving 46 ft 4 in.
  3. Add 10% for miters, offcuts and the piece you cut backwards: 50 ft 11 5/8 in. At 16' a stick that is 4 of them.

Baseboard by room size, two doorways taken out, 10% waste

Baseboard by room size, two doorways taken out, 10% waste
RoomPerimeterAfter doorwaysWith waste16' sticks12' sticks
10' × 10'40'34 ft 4 in37 ft 9 3/16 in34
10' × 12'44'38 ft 4 in42 ft 2 in34
12' × 12'48'42 ft 4 in46 ft 6 13/16 in34
12' × 14'52'46 ft 4 in50 ft 11 5/8 in45
14' × 16'60'54 ft 4 in59 ft 9 3/16 in45
16' × 20'72'66 ft 4 in72 ft 11 5/8 in57

Worth knowing

  • 10% is right for a simple rectangular room. A room with bay windows, alcoves or a lot of short runs wants 15% or more — every corner is two miters and every miter is an offcut.
  • Longer stock means fewer joints in the middle of a wall, which is where a joint shows. Buy the longest sticks that will get into the room and up the stairs, not the ones that are easiest to carry.
  • Cope inside corners rather than mitering them. A coped joint closes up as the house moves; a mitered one opens, and it opens where the light catches it.
  • Scarf joints in the middle of a long wall, cut at 45° so one piece laps the other, and land them over a stud. A butt joint in baseboard opens within a season.