How Much Baseboard Do I Need? Formula, Doors & Worked Examples

Planning estimate — measure at baseboard height, not at the floor. Baseboard runs the walls minus the doorways, plus waste for corners. This guide gives you the formula, then run your room through our baseboard calculator.

The formula

Net feet = 2 × (length + width) − 3 ft per doorway. Order feet = ceiling(net × (1 + waste)). Sticks = ceiling(order feet ÷ stick length). A 12 × 12 ft room with 1 doorway: 2 × 24 = 48 ft of perimeter, minus 3 ft = 45 ft net, times 1.10 waste = 49.5, rounded up to 50 ft to order, and 50 ÷ 8 = 6.25, rounded up to 7 sticks of 8 ft.

The door deduction

Each standard interior doorway deducts 3 ft — the standard door width (30–36 inches) plus casing. Baseboard stops at the casing on both sides; it never runs behind a door. Count cased openings without a door the same way. For double doors or wide cased openings, deduct the actual width: a 6 ft opening counts as roughly two doorways. Closet doors count too if the baseboard would otherwise run across them — walk the room and count every opening the trim must stop at.

Corners and waste

Waste of 10% suits a plain rectangle with four corners. Use 15% for rooms with many corners, bay windows, short wall jogs, or angled walls: every mitered outside corner and coped inside corner wastes a few inches, and the first cope on a profile often needs a second attempt. If the profile is unusual or the supplier is far away, buy one spare stick beyond the count — baseboard from a different mill run can differ slightly in profile and finish.

Stick lengths and joints

Baseboard is sold in 8 ft sticks most commonly, with 12 ft and 16 ft also available. Longer sticks mean fewer joints on long walls, but they are harder to transport and to maneuver around corners. On a wall longer than one stick, join the pieces with a scarf joint (two 45-degree cuts that overlap) rather than a butt joint — a scarf joint stays tight as the wood moves with the seasons, while a butt joint opens into a visible crack.

Worked examples

1. 12 × 12 ft room, 1 doorway, 8 ft sticks, 10% waste: 48 − 3 = 45 ft net, 50 ft to order, 7 sticks.
2. 10 × 14 ft room, 2 doorways, 12 ft sticks, 10% waste: 48 − 6 = 42 ft net, 47 ft to order (46.2 rounded up), 4 sticks.
3. 20 × 16 ft living room, 3 doorways, 8 ft sticks, 15% waste: 72 − 9 = 63 ft net, 73 ft to order (72.45 rounded up), 10 sticks.

Common mistakes

Three errors cover most baseboard shortages: measuring the floor instead of the walls (a bowed wall adds inches at baseboard height), forgetting to deduct doorways at all (a three-door room overbuys by 9 ft), and using butt joints on long walls that open up later. Measure each wall separately on an irregular room and add the walls — never estimate a room's perimeter from its floor area.

Frequently asked questions

The rest of the room

Baseboard is the last trim — the laminate flooring calculator covers the floor it meets, and the paint calculator covers the walls above it.