Flooring for a 20×20 room by waste allowance
| Waste | Sq ft to buy | Boxes (20 sq ft) | Boxes (24 sq ft) |
|---|---|---|---|
| 5% | 420 sq ft | 21 | 18 |
| 10% | 440 sq ft | 22 | 19 |
| 15% | 460 sq ft | 23 | 20 |
| 20% | 480 sq ft | 24 | 20 |
A 400 sq ft room is typical of a large living area or basement. Box sizes vary a lot between products (roughly 15–30 sq ft), so enter your exact box coverage in the calculator above.
The math
20 ft × 20 ft = 400 sq ft
× 1.10 waste = 440 sq ft
÷ 20 sq ft/box = 22 boxes (rounded up)
Also plan 400 sq ft of underlayment if your planks don't have it attached, and about 80 linear feet of baseboard or quarter-round for the perimeter (less door openings).
Common questions
How many square feet is a 20x20 room?
400 square feet.
How many boxes of flooring for a 20x20 room?
22 boxes of 20 sq ft each with 10% waste, or 19 boxes of 24 sq ft.
Want the full method, tips and other sizes? See the flooring calculator guide.