Flooring Calculator
Turn a room's length and width into the number of flooring boxes to buy, with a waste cushion baked in for cuts and mistakes.
How it works
Start with the floor area: length times width. A 15-by-12 room is 180 square feet. That's the raw amount you'd need if every plank landed perfectly and nothing ever got cut.
Real installs waste material at the edges, around doorways, and when you rip a board to fit the last row. Adding 10 percent bumps that 180 up to 198 square feet, which is the number you actually shop against.
Flooring is sold by the box, and each box covers a set area — often around 20 square feet for laminate or vinyl plank. We divide the area-with-waste by the box coverage and round up, since you can't buy a partial box.
Frequently asked questions
How much waste should I add for flooring?
Ten percent is the usual starting point for a straight-laid rectangular room. Bump it to 15 percent for diagonal layouts, busy floor plans with lots of corners, or a patterned wood you have to match across boards.
Where do I find the coverage per box?
It's printed right on the carton and on the product page — something like '19.63 sq ft per box.' Plug that exact number in, because box coverage varies a lot between plank sizes and brands.
Should I buy an extra box beyond what this shows?
It's smart to keep one spare box for future repairs, since dye lots change and a plank you buy in two years may not match. That's separate from the waste percentage, which only covers the install itself.