Baseboard Calculator – How Much Baseboard Do I Need? | CalcLoft
Find out exactly how many sticks of baseboard you need for any room — including door openings, waste and your board length.
How to measure a room for baseboard
Baseboard runs along the bottom of every wall, so for a rectangular room the starting point is the full perimeter of the floor:
Perimeter = (length + width) × 2
Each interior door interrupts the run — the baseboard usually stops at the door casing. Subtract about 3 ft per door to get the net run you actually have to cover:
Net run = (length + width) × 2 − (doors × 3 ft)
For example, a 12 × 12 ft room has a 48 ft perimeter. With one standard door the net run is 45 ft. Add roughly 10% for miters, cutoffs and mistakes, then round up to whole boards.
Baseboard amounts for common room sizes
Figures below assume one standard door and 8-ft boards. Minimum sticks = net run ÷ 8, rounded up. Order sticks = net run × 1.10 ÷ 8, rounded up (includes the 10% waste buffer).
| Room size | Perimeter | Net run (1 door) | 8-ft sticks, minimum | 8-ft sticks, with 10% waste |
|---|---|---|---|---|
| 10 × 10 ft | 40 ft | 37 ft | 5 | 6 |
| 12 × 12 ft | 48 ft | 45 ft | 6 | 7 |
| 12 × 14 ft | 52 ft | 49 ft | 7 | 7 |
| 14 × 16 ft | 60 ft | 54 ft | 7 | 8 |
| 20 × 20 ft | 80 ft | 74 ft | 10 | 11 |
How much baseboard for a 12x12 room?
A 12 × 12 ft bedroom with one door has a 45 ft net run. Adding 10% waste gives 49.5 ft, so you need 7 sticks of 8-ft baseboard (56 ft purchased). Switching to 12-ft boards drops that to 5 sticks. Use the calculator above to check your exact room.
Related guides
Baseboard calculator FAQ
Do door openings reduce the amount of baseboard?
Yes. The calculator subtracts about 3 ft of run for each door. A standard interior door opening is roughly 32 in wide plus casing, and the baseboard stops at the frame instead of running through the doorway. Windows usually do not interrupt baseboard, so they are not deducted.
Should I buy extra baseboard beyond the minimum?
Yes — that is exactly what the waste field does. Every corner needs a 45° miter cut, and walls are rarely perfectly square, so you will lose length to cutoffs and mistakes. The default 10% buffer covers that; bump it to 15% for older homes with uneven floors or rooms with many corners.
Do longer 12-ft boards mean I need fewer sticks?
Yes. Take a 12 × 12 ft room: 45 ft net run plus 10% waste is 49.5 ft, which works out to 7 sticks of 8-ft board but only 5 sticks of 12-ft board — or 4 sticks of 16-ft board. Longer boards mean fewer seams and cuts, but they are heavier and harder to maneuver into tight spaces.
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