Estimate how much flooring to buy — total square footage plus number of boxes — from your room size, with waste.
buy = area × (1 + waste); boxes = buy ÷ box_coverage
Add a waste factor to the room area, then divide by the coverage printed on each box.
NWFA recommends 10–15% for hardwood; more for diagonal or feature layouts and natural-variation materials.
A 15 x 20 ft room is 300 square feet. Hardwood and laminate carry about 10% waste for cuts and board culling, so you'd buy about 330 square feet. If each box covers 20 square feet, that's 17 boxes.
For a diagonal install or a room with many jogs and closets, go to 15% waste. Always open and inspect boxes before installing, and rack boards from several boxes at once so any color variation blends across the floor rather than pooling in one area.
Flooring waste factors follow NWFA guidance. Buy from one dye lot to avoid shade differences mid-project.
About 10% for a straight layout, 15% for diagonal or patterned installs.