Baseboard Calculator

Find linear feet of baseboard for a room.

Room length

Room width

Total door width(optional)

Openings to subtract

Waste allowance(optional)

Default 10%

Results update as you type.

Baseboard needed

—

8-ft pieces—

How it works

Baseboard, or skirting, runs along the bottom of a room's walls, and this calculator finds how much you need from the room dimensions. You enter the room length and width, subtract the total width of doorways where no baseboard goes, choose a waste allowance, and it returns the linear feet required and the number of standard eight-foot pieces to buy. The core of the estimate is the room perimeter, twice the length plus twice the width, since baseboard follows the walls all the way around. Door openings are subtracted because trim is not installed across them, though you generally do not subtract windows since baseboard usually runs beneath them. A waste allowance of around ten percent is wise because mitered corners, inside and outside, produce offcuts, and it is prudent to have spare material that matches, since dye lots and profiles can vary between purchases. Buying by the piece matters because baseboard comes in fixed lengths, commonly eight feet, and you cannot use partial sticks beyond what you cut. This calculator helps you order the right amount for a renovation or new build without running short or badly overbuying. Enter your room dimensions and door widths to compute the baseboard needed.

Formula

Linear feet = (perimeter − doors) × (1 + waste)

The calculator finds the room perimeter as twice the length plus twice the width, subtracts the total width of door openings where baseboard is not installed, and multiplies by one plus the waste fraction. Dividing by eight feet and rounding up gives the number of standard baseboard pieces to buy, allowing for miter cuts and offcuts.

Source:Trim estimation

We review all our tools from time to time to ensure accuracy.

Worked example

Room length:12Room width:10Total door width:3Waste allowance:10

Perimeter 44 ft − 3 ft doors = 41 ft × 1.10 ≈ 45.1 ft, so 6 eight-foot pieces.

How to use this calculator

1
Enter your values
Enter room length and room width.
2
Adjust the options
Adjust total door width and waste allowance if they apply — sensible defaults are already set.
3
Read your result
Baseboard needed updates instantly as you type — no button to press.

Frequently asked questions

How do I calculate baseboard for a room?

Find the room's perimeter by adding twice the length and twice the width, subtract the widths of doorways, and add a waste allowance for cuts. Divide by the length of your baseboard stock to get the number of pieces. The calculator does all of this when you enter the room dimensions and door widths.

Do I subtract windows and doors?

Subtract door openings, since baseboard is not installed across a doorway. Do not subtract windows, because baseboard normally continues along the wall beneath them. If you have other floor-level openings such as a fireplace or built-in, subtract those widths too, entering the total as the door width in the calculator.

How much waste should I add?

About ten percent is a sensible allowance for baseboard because mitered corners create offcuts and mistakes happen. Rooms with many corners or short wall segments waste more, so consider fifteen percent. Buying a little extra also guards against damage during installation and ensures you have matching material if you need a repair later.

What length does baseboard come in?

Baseboard is commonly sold in eight-foot lengths, though twelve-, fourteen-, and sixteen-foot pieces exist and reduce the number of joints on long walls. This calculator assumes eight-foot pieces by default. Longer stock means fewer seams but is harder to transport, so balance appearance against practicality for your room.

Should I buy by length or by piece?

Buy by the piece, because baseboard comes in fixed lengths and you pay for whole sticks. Knowing the linear feet is useful, but converting to pieces tells you how many to actually purchase. The calculator gives both, rounding the pieces up so you have enough whole lengths to complete the room.