How Much Flooring Do I Need?
Three steps, no guesswork: measure the room, add waste for cuts, then round up to whole boxes using the coverage on your own box. Every number below is worked out with the same maths as the calculator on the home page.
Step 1: Measure the room area
Floor area = length × width
Measure each room wall to wall in feet and multiply length by width. For an L-shaped room, split it into rectangles and add the parts — see how to calculate square footage by hand for the full measuring steps. Or skip the arithmetic: the square footage calculator totals several areas for you.
Step 2: Add waste for cuts
Area to order = floor area × (1 + waste %)
The bare area is what ends up on the floor; cuts at walls, doorways and corners, plus the odd damaged piece, use more. A 12 × 12 room is 144.00 sq ft, and with the usual 10% waste allowance that is 158.40 sq ft to order. Diagonal layouts and small, cut-heavy rooms often need 15% instead — change the waste percentage in the calculator to match your layout.
Flooring to order by room size (10% waste)
Rectangular rooms, measured in feet. The “to order” column is the floor area plus 10% — always round up to whole boxes from there.
| Room size (ft) | Floor area | To order (+10%) |
|---|---|---|
| 10 × 10 | 100.00 sq ft | 110.00 sq ft |
| 10 × 12 | 120.00 sq ft | 132.00 sq ft |
| 12 × 12 | 144.00 sq ft | 158.40 sq ft |
| 12 × 16 | 192.00 sq ft | 211.20 sq ft |
| 15 × 20 | 300.00 sq ft | 330.00 sq ft |
| 20 × 20 | 400.00 sq ft | 440.00 sq ft |
Step 3: Round up to whole boxes
Boxes = round up (area to order ÷ coverage of one box)
Flooring is sold by the box, and every product covers a different area per box — read the figure on your own box or product listing. Worked example, using a box that covers 20 sq ft: for the 12 × 12 room above, 158.40 ÷ 20 = 7.92, so you order 8 boxes. Always round up, and keep one unopened box if you can: a matching spare is worth far more than a second trip for a different dye lot.
The same idea works for tile: divide the area to order by the area of one tile. A 12 × 12 inch tile covers 1 sq ft, so the same 12 × 12 room needs 158.40 sq ft ÷ 1 = 159 tiles after rounding up.
A note on prices
This site does not quote material prices: the price per square foot is whatever your supplier charges, and you enter it yourself in the calculator if you want a cost estimate. The calculator’s estimate is simply area to order × the price you typed in — nothing more.
Results here are estimates for planning and ordering. Confirm quantities with your supplier or installer before buying.