How much flooring to buy
Start with the room area, then add a waste allowance for cuts and mistakes: flooring = length × width × (1 + waste ÷ 100). A 12 × 10 ft room is 120 square feet; with 10% waste you buy 132 square feet. Round up to whole boxes. Measure the room first with the square footage calculator.
How to use this calculator
Enter the room length and width in feet and a waste allowance. The result shows the square footage to purchase. For L-shaped rooms, split into rectangles, calculate each, and add them before applying waste. For tile, the piece count comes from the tile calculator instead.
How much waste to allow
| Install | Waste |
|---|---|
| Straight lay, simple room | 5–10% |
| Diagonal or patterned | 15% |
| Herringbone / complex | 15–20% |
Buy by the box and keep extras
Flooring is sold by the box covering a set area, so divide your total by the box coverage and round up. Keep a spare box from the same batch for future repairs — dye lots vary between production runs. To compare flooring cost against the room, see the price per square foot calculator.
Let the flooring acclimatise in the room for 48 to 72 hours before installation so it settles at the room's humidity, and leave the expansion gap the manufacturer specifies at every wall. Neither step changes the quantity, but skipping them can ruin an otherwise perfect order. Finish the job by ordering trim with the baseboard calculator.
Frequently asked questions
- How do I calculate flooring needed?
- Multiply room length by width for the area, then add a waste allowance. A 12×10 ft room with 10% waste needs 132 square feet.
- How much waste should I add for flooring?
- About 5–10% for a straight lay in a simple room, 15% for diagonal or patterned, and up to 20% for herringbone or complex layouts.
- How do I figure flooring for an L-shaped room?
- Split the room into rectangles, calculate each area, add them together, then apply your waste allowance.
- Why keep a spare box of flooring?
- Color and texture vary slightly between production batches, so a leftover box from the same lot makes future repairs match.
- How do I turn square footage into boxes?
- Divide your total by the coverage printed on the box and round up to the next whole box. If a box covers 22 sq ft, 132 square feet needs six boxes, and part-boxes are rarely sold.