How Much Baseboard Do I Need?
Baseboard follows the wall perimeter, not the floor area - so the trick is turning room size into linear feet, then into lengths to buy. Here is the method, tables by room size and by square footage, and the per-square-foot rule of thumb when all you have is a floor area.
By the Calculate My Reno Team / Published
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Open the Skirting Board Calculator
Baseboard is a linear material: it runs around the foot of the walls, so what you need is the wall perimeter, less the doorways - not the floor area. The whole job is turning room size into linear feet, then into lengths to buy.
Skip the math
Enter each room by its length and width (or its perimeter for an L-shaped room), add the doorways, and the baseboard calculator returns the linear feet and the number of stock lengths, with waste. The rest of this guide is how it works, so you can check the number.
The quick formula
perimeter = 2 × (length + width) (or measure the perimeter directly)
run = perimeter − doorway widths (per room, never below zero)
lengths = ceil( total run × waste ÷ stock length )
Add 10% waste for a simple room, 15% where there are lots of corners and short walls, and buy the longest stock that fits each wall to cut down on joints.
Baseboard by room size
Linear feet of wall for a rectangular room, before deducting doorways (take off about 3 ft per doorway):
| Room size | Perimeter (linear ft) |
|---|---|
| 8 × 10 ft | 36 ft |
| 10 × 12 ft | 44 ft |
| 12 × 12 ft | 48 ft |
| 12 × 15 ft | 54 ft |
| 15 × 20 ft | 70 ft |
| 20 × 20 ft | 80 ft |
Baseboard by square footage (rule of thumb)
When all you have is a floor area, estimate the perimeter as 4 × the square root of the area for a square-ish room, then add 10-30% for a home split into several rooms, and take off the doorways:
| Floor area | Single square room | Whole home (multiple rooms) |
|---|---|---|
| 500 sq ft | ~90 ft | ~100 - 130 ft |
| 1,000 sq ft | ~125 ft | ~150 - 200 ft |
| 1,200 sq ft | ~140 ft | ~175 - 250 ft |
| 1,500 sq ft | ~155 ft | ~200 - 280 ft |
| 2,000 sq ft | ~180 ft | ~230 - 330 ft |
The whole-home column is wider because internal walls add perimeter that a single open room does not have. It is an estimate - the only reliable way is to measure each room, which is what the calculator does.
Do not forget the second profile
If you are also running crown molding, picture rail or coving at the ceiling, that is a separate run - and it covers the full perimeter with no doorway deductions, because nothing interrupts it up there. See how much crown molding do I need, or tick the second-profile option in the calculator.
Worked example
A 12 ft × 15 ft living room with two 3 ft doorways, baseboard in 16 ft lengths, 10% waste:
- Perimeter: 2 × (12 + 15) = 54 ft.
- Doorways: 2 × 3 = 6 ft off, so run = 48 ft.
- Add 10% waste: 48 × 1.10 = 52.8 ft.
- Lengths: 52.8 ÷ 16 = 3.3, rounded up = 4 lengths.
Round up to whole lengths, keep one spare for a blown mitre, and price the run with baseboard installation cost.
Frequently asked questions
How much baseboard do I need for 1,200 square feet?
Square footage only gives a rough guide, because baseboard follows the wall perimeter, not the floor. For a single open square room, the perimeter is about 4 × the square root of the area - so 1,200 sq ft is near 140 linear feet. But a real 1,200 sq ft home is split into rooms by internal walls (which add perimeter) and has doorways (which take some away), so it usually lands around 175 to 250 linear feet once you measure room by room. Run each room through the calculator for the real number.
How do I calculate baseboard from square footage?
Use the perimeter rule of thumb: for a square-ish room, linear feet of wall is roughly 4 × the square root of the floor area. A 144 sq ft room (12 × 12) gives 4 × 12 = 48 ft. Multiply by about 1.1 to 1.3 for a home divided into several rooms (more internal walls means more perimeter), then subtract the doorways. It is an estimate - measuring each room's walls is always more accurate.
How much extra baseboard should I buy for waste?
Add about 10% for a simple room and 15% where there are lots of corners and short walls. Each mitre and scarf joint eats a little off the stick, and the last offcut on a wall is often too short to reuse elsewhere. Buying the longest lengths that fit your walls means fewer joints and less waste - and it is cheaper to have one spare length than to stop the job a board short.
Do I subtract doors and windows from baseboard?
Subtract doorways and floor-length openings, because the baseboard stops at each side of them. Do not subtract windows - the baseboard runs along the wall beneath a window. The calculator deducts each doorway from its own room only, so a wide opening in one room never reduces another room's run.
How many lengths of baseboard is that?
Take the total linear feet, add your waste allowance, then divide by the length of one stock piece (commonly 8, 12, 14 or 16 ft) and round up. So 100 ft of run with 10% waste is 110 ft; in 16 ft lengths that is 110 ÷ 16 = 6.9, rounded up to 7 lengths. Longer stock means fewer joints. The calculator does this step for whatever stock length you pick.