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Flooring & TileBaseboard Calculator — How Much Trim Do I Need?
Enter the room’s length and width to estimate baseboard or trim — the perimeter plus 10% for miter cuts, and how many 8-foot pieces to buy.
How this calculator works
We figure the room perimeter — 2 × (length + width) — add 10% for miter cuts and waste, and divide by 8 ft to count standard pieces. The same approach works for crown molding and shoe molding.
What changes how much you need
- Subtract about 3 ft for each doorway if your room has several.
- Mitered corners waste material — 10% is a safe allowance.
- Trim comes in 8, 12, and 16-ft lengths; longer pieces mean fewer seams on long walls.
- Buy one or two extra pieces for mistakes and future repairs.
Frequently asked questions
How much baseboard do I need for a room?
Add up the perimeter (2 × length + 2 × width), subtract doorways, and add about 10% for cuts. A 14×12 ft room needs roughly 57 linear feet.
How long are baseboard pieces?
Commonly 8, 12, or 16 feet. This calculator counts 8-ft pieces; divide the linear feet by your length for others.
How much extra should I buy?
About 10% over the perimeter for miter cuts, plus a spare piece or two.