Inputs
Example data table
These sample rooms show how totals change when you subtract openings.
| Room | Input | Doors | Other openings | Net baseboard |
|---|---|---|---|---|
| Living Room | 18 × 12 ft | 2 | 0 ft | ~54 ft |
| Hallway | 10 × 4 ft | 1 | 0 ft | ~25 ft |
| Kitchen | 12 × 10 ft | 1 | 0 ft | ~41 ft |
Formula used
If excluded openings exceed a room perimeter, net is capped at zero.
How to use this calculator
- Pick feet or meters to match your tape measure.
- Select rectangular rooms or perimeter-only mode for irregular spaces.
- Enter each room’s dimensions, then add doors and other openings.
- Set a waste percentage for cuts, corners, and mistakes.
- Choose a stock piece length to estimate how many pieces to buy.
- Press Calculate to see totals, then download CSV or PDF.
Project notes
Planning baseboards for accurate coverage
Baseboard trim protects lower walls from knocks, moisture splashes, and routine cleaning. This calculator turns room measurements into a dependable purchase list by converting perimeter into usable baseboard length. It supports multiple rooms, mixed openings, and an adjustable waste factor so you can plan for miter cuts, scarf joints, and end trimming without overbuying excessively. Record units consistently for clean planning.
Measuring rooms with corners and transitions
Start by measuring each room with a tape and recording length and width, or enter a known perimeter for curved or irregular spaces. Include bump-outs, closet returns, and short wall segments because these add real footage. For open plans, split the space into logical zones so you can capture partial walls, islands, and stair runs clearly. When measuring, note ceiling height changes only if they affect trim stops or transitions.
Accounting for doors, vents, and built-ins
Next, subtract areas where trim will not be installed. Typical exclusions include doorways, sliding doors, fireplaces with raised hearths, and floor-to-ceiling cabinetry. Use a realistic door width and add any other openings as a single total per room. The tool caps net length at zero if exclusions exceed perimeter, which avoids negative results. If you plan shoe molding separately, do not include it in the baseboard length figure.
Choosing stock lengths, joints, and waste
After net length is calculated, add a waste percentage. A 5–10% allowance often suits straight runs in new construction, while 10–15% is common for older homes with out-of-square corners. Stock piece length affects joints and handling: longer boards reduce seams but may be harder to transport. The piece estimate rounds up, ensuring full boards are purchased. For stained trim, increase waste slightly to match grain and color.
Estimating budget and purchase quantities
Finally, the cost section helps align the trim plan with your budget. Enter a price per foot or meter and compare scenarios such as primed profiles versus hardwood. Use the results to stage purchases room-by-room, confirm you have enough inside and outside corner blocks, and prepare for caulk, filler, and touch-up paint during installation. Save offcuts for short returns and closet spans.
FAQs
Should I measure in feet or meters?
Use the unit that matches your tape measure. The calculator keeps all math consistent, then reports totals, piece counts, and costs in the same unit you selected.
What waste percentage is realistic?
For straight runs, 5–10% often works. For many corners, short returns, or stained trim where matching matters, 10–15% is safer. The tool applies waste after subtracting openings.
How do I handle irregular rooms?
Switch to perimeter-only mode and enter the measured perimeter directly. This is ideal for curved walls, angled bays, or open areas where length and width do not describe the space well.
Do I subtract every doorway?
Subtract openings where baseboard will not be installed, such as doorways without trim across the threshold. If you plan to run trim behind a casing return, reduce the door subtraction accordingly.
Why does piece count round up?
Trim is bought in full lengths. Rounding up ensures you purchase enough boards even when the final partial length is small. It also helps cover defects, end checks, and cut mistakes.
Is the cost estimate exact?
It is a planning figure based on your entered price per foot or meter. Taxes, delivery, corner blocks, caulk, nails, and paint are not included, so keep a small contingency for supplies.