How many sticks of trim should I buy?

Divide the net run plus waste by your stock length. 48 ft of run with 10 % waste is 52.8 ft; at 8 ft per stick that is 7 sticks. Prefer longer sticks on long walls to avoid mid-wall joints.

Why add waste for trim?

Every outside corner is a mitered pair that wastes a few inches, scarf joints on long runs overlap, and the odd cut goes wrong. Ten percent is a safe allowance; add more for a room with many corners or a complex profile.

Does this work for crown molding?

Yes, with one change: do not subtract the doors, because crown runs continuously around the ceiling above them. Use the full perimeter, and bump the waste up — crown's compound miters are less forgiving.

Baseboard & Trim Calculator

Enter the room and door openings to get linear feet of baseboard and the number of stock sticks to buy — miter waste included.

Inputs

Room size

ft ×

Room size, second side

Doors2

Door width

Stock length

Waste

Results update as you type — no submit

Trim to buy

7 × 8 ft sticks

≈ 14.63 m of trim

Trim run (linear)48 ft (14.63 m)

Room perimeter54 ft

Door openings6 ft (2 doors)

Formula

run = perimeter 54 − doors 6 = 48 ft × 1.1
sticks = ceil(52.8 ÷ 8) = 7

Diagram — trim runNTS

MeasureShedmeasureshed.com/calculator/baseboard-trim-calculator

Baseboard & trim — material listUNITS: FT · SCALE: NTS

Inputs

Room size12 × 15 ft

Doors2

Door width36 in

Stock length8 ft

Waste+10%

Results

Sticks to buy7 × 8 ft

Trim run48 ft

Room perimeter54 ft

Door openings6 ft

Trim runNTS

Shopping list

☐ 7 × baseboard, 8 ft

Formula

run = 54 − 6 = 48 ft

sticks = ceil(52.8 ÷ 8) = 7

Estimates for planning only — verify before purchaseSHEET 1 OF 1

How it works

Baseboard runs around the whole room, so the starting length is the perimeter: twice the length plus twice the width. Then subtract the doorways, because trim stops at each opening — a standard `36"` door removes about `3 ft` of run. That gives the net linear feet of baseboard you actually install.

Trim is sold in fixed stock lengths — `8`, `12`, `14`, and `16 ft` are the common ones at home centers. Divide the net run, plus a waste allowance, by the stock length to get the number of sticks. The waste (about `10 %`) covers the outside-corner miters that eat a few inches at each joint and the occasional bad cut.

Longer sticks mean fewer joints on long walls, which look cleaner, but they are harder to carry and store. Because you buy whole sticks, the count rounds up. The same method works for crown molding, chair rail, and shoe molding — just leave the door openings in for crown, since it runs unbroken above them.

Worked example

Room 12 ft × 15 ft · 2 doors (36") · 8 ft sticks · +10% waste
perimeter = 2 × (12 + 15) = 54 ft
doors = 2 × 3 = 6 ft → net run = 48 ft
sticks = 48 × 1.10 ÷ 8 = 6.6 → 7 sticks

Questions about trim

Take the room perimeter and subtract the door openings. A 12 × 15 ft room is 54 ft around; two 3 ft doors leave 48 ft of baseboard. Add about 10 % for miter cuts.

SOURCES — Standard US door widths & molding stock lengths (Home Depot / Lowe's)

Estimates for planning only — verify before purchase