How much flooring do you need for a 12×18 room?

A 12×18 ft room is 216 square feet. With 10% extra for cuts, buy 237.6 sq ft of flooring — 12 boxes if each box covers 20 sq ft.

Change the numbers

The calculator below is pre-filled for this project. Adjust any value — including feet and inches — and the results update instantly.

Your results

Flooring to buy238 sq ft

Boxes (20 sq ft each)12

Room area216 sq ft

Extra for cuts & waste21.6 sq ft

How much flooring do you need for a 12×18 room — diagram

Flooring for a 12×18 room by waste allowance

Waste	Sq ft to buy	Boxes (20 sq ft)	Boxes (24 sq ft)
5%	226.8 sq ft	12	10
10%	237.6 sq ft	12	10
15%	248.4 sq ft	13	11
20%	259.2 sq ft	13	11

A 216 sq ft room is typical of a primary bedroom or living room. Box sizes vary a lot between products (roughly 15–30 sq ft), so enter your exact box coverage in the calculator above.

The math

12 ft × 18 ft = 216 sq ft × 1.10 waste = 237.6 sq ft ÷ 20 sq ft/box = 12 boxes (rounded up)

Also plan 216 sq ft of underlayment if your planks don't have it attached, and about 60 linear feet of baseboard or quarter-round for the perimeter (less door openings).

Common questions

How many square feet is a 12x18 room?

216 square feet.

How many boxes of flooring for a 12x18 room?

12 boxes of 20 sq ft each with 10% waste, or 10 boxes of 24 sq ft.

Want the full method, tips and other sizes? See the flooring calculator guide.

Last reviewed November 1, 2026. Results are estimates — confirm with your supplier.

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