Measure the room and get the square feet and number of boxes of flooring or tile to order, including extra for cuts.
How to measure for flooring
- Measure the length and width of the room at the widest points, in feet.
- Multiply them to get the area. Split L-shaped rooms into rectangles and add them, or put closets in the extra area box.
- Add a waste allowance for cuts and mistakes: 10% is standard, 15% for diagonal or herringbone layouts.
- Divide by the square feet in a box and round up.
A 12 × 14 ft room is 168 sq ft. With 10% waste that's 184.8 sq ft, so with boxes of 20 sq ft you'd buy 10 boxes.
Tips
- Keep a spare box or two from the same batch for future repairs, since colors vary between production runs.
- Let laminate and wood acclimate in the room for 48 hours before installing.
- Remember underlayment, transitions and trim, which are sold separately.
How we checked this
Before every update, this calculator is run in a real browser with these known answers, and it must match all of them:
- 12 × 14 room with 10% waste: 185 sq ft, 10 boxes of 20 ✓
Last checked October 26, 2026. Spotted something wrong? The math is done in your browser with the formula shown on this page, so you can check any result by hand.
Questions people ask
How much extra flooring should I buy?
10% is standard. Use 15% for diagonal or patterned layouts and up to 20% for rooms with lots of corners.
How many boxes of flooring do I need for 200 sq ft?
With 10% waste you need 220 sq ft. At 20 sq ft per box, that's 11 boxes.
How do I measure an L-shaped room?
Split it into two rectangles, find each area, and add them together.