How we worked it out
Updated as you change the numbers.
- Perimeter = 2 × (12 + 10) = 44 ft.
- Less 1 doorway(s) × 36 in ÷ 12 = 3 ft, leaving 41 ft.
- Pieces = 41 × 1.1 ÷ 16 ft = 2.82, rounded up to 3.
Method and assumptions
Trim runs around the perimeter of the room. Baseboard stops at doorways, so their widths are subtracted; crown molding and chair rail usually run all the way around. The calculator adds your allowance for miters and divides by the stock length.
This is a total-length estimate. For fewer joints, plan pieces wall by wall: each wall shorter than a stock piece can take one piece with no joint.
Tips
- Cope inside corners on baseboard and crown rather than mitering them; coped joints stay tight as the house moves.
- Buy one extra piece to practice crown cuts on.
Questions
How much baseboard do I need for a 12 × 10 room?
The perimeter is 44 ft. Less one 36 in doorway, that is 41 ft, or about 45 ft with 10% extra: three 16 ft pieces.
Sources
Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.