Baseboard Calculator
Measure baseboard or trim by room perimeter.
Enter your room dimensions and the total width of any doorways to subtract, and get the linear feet of baseboard or trim needed plus the number of pieces at your chosen length.
How it works
Baseboard follows the room perimeter: 2 × (length + width). Subtract doorway openings, then divide by your trim piece length and round up. Add a little extra for miter cuts at corners and any mistakes.
Worked example
For a 12 ft × 14 ft room, the perimeter is 2 × (12 + 14) = 52 linear feet. Subtract door openings — a standard 3 ft door leaves 49 ft. Trim is sold in 8, 12, and 16 ft lengths, so buy enough sticks to cover 49 ft plus about 10% for miter cuts and mistakes: roughly 54 ft, or four 16-ft lengths.
What changes your estimate
- Doorways reduce the run. Subtract each door's width from the perimeter, but keep openings to closets and cased archways if they get trim.
- Miter waste. Inside and outside corners and scarf joints eat material. A 10% allowance covers a typical room; ornate rooms with many corners need more.
- Stock lengths matter. Buying in longer lengths reduces visible seams on long walls — plan which wall gets the full-length pieces.
- Paint-grade vs. stain-grade. Stain-grade trim needs continuous grain match and tighter cuts, so add extra for selecting and culling pieces.
Frequently asked questions
How much baseboard do I need?
Add up the room perimeter (2 × length + 2 × width), subtract doorway widths, then divide by your piece length. A 12×10 room with one 3-ft doorway needs about 41 linear feet.
How many pieces of trim is that?
Divide the linear feet by your trim length and round up. 41 linear feet in 8-ft pieces is 6 pieces.
Should I buy extra trim?
Yes — add about 10% for miter cuts at corners and the occasional bad cut.
Is this calculator free and private?
Yes. Every CubicCabin calculator runs entirely in your browser, so the numbers you enter are never uploaded or stored. There's no sign-up, no limits, and it keeps working even if you lose connection after the page loads.