How much flooring to buy
Area = Length × Width (add each room)
Flooring to buy = Area × (1 + Waste) Waste: about 10% straight, 15% diagonal or herringbone
Boxes = Flooring to buy ÷ Sq ft per box, rounded up Carpet (sq yd) = Flooring to buy ÷ 9
Example: a 15 × 12 ft room is 180 sq ft. With 10% extra you need 198 sq ft, which is 10 boxes of laminate at 20 sq ft a box (200 sq ft), plus 2 rolls of underlayment. In carpet it's 22 square yards.
Flooring tips
- Buy from one batch (lot number) so color matches, and keep a spare box for repairs.
- Acclimate laminate and hardwood in the room for 48 hours before installing.
- Underlayment: laminate needs it; many vinyl planks have it attached. Use a vapor barrier over concrete.
- Closets and hallways each count as their own rectangle; L-shaped rooms split into two.
Working with tile instead? Use the tile calculator. For irregular rooms, try the square footage calculator.
Frequently asked questions
How much extra flooring should I buy?
About 10% for a straight layout in an ordinary room, and 15% or more for diagonal or herringbone patterns or rooms with lots of corners.
How many boxes of flooring for 500 square feet?
With 10% extra you need 550 sq ft. At 20 sq ft a box that's 28 boxes; check the label, since boxes range from about 15 to 30 sq ft.
How do I convert square feet to square yards for carpet?
Divide by 9. A 180 sq ft room is 20 square yards before waste.
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