Flooring Calculator
Enter your room area, coverage per box, and a waste allowance to estimate how many boxes of flooring to buy.
Last updated: September 22, 2026
Frequently asked questions
How many boxes of flooring do I need for 250 sq ft?
At 22 sq ft per box with a 10% waste allowance, 250 sq ft needs about 13 boxes.
Why do I need extra flooring for waste?
Cuts around doorways, closets, and pattern matching use extra material - a 10–15% allowance keeps you from running short mid-project.
Does the waste percentage change based on the flooring pattern?
Yes - a straight-lay pattern typically needs only 5-10% extra, while diagonal layouts or patterns requiring precise seam matching (like herringbone) can need 15-20% extra due to more angled cuts and discarded offcuts.
Should I buy extra flooring for future repairs?
Yes - beyond the waste allowance for cutting during installation, many installers recommend keeping one full extra box aside so replacement pieces match the original dye lot if a plank or tile is ever damaged later, since manufacturers change color batches over time.
How many boxes do I need for a 12×15 ft room with 20 sq ft coverage per box?
12×15 ft is 180 sq ft. With a 10% waste allowance that's 198 sq ft of material needed, which at 20 sq ft per box rounds up to 10 boxes.
Should I subtract closets and doorway openings from the room area before calculating?
Usually not - most installers measure the full floor area including closets and door openings and let the waste allowance absorb the small amount of extra material, rather than subtracting minor cutouts and risking running short mid-job.
What's the difference between this flooring calculator and the square footage calculator?
Use the square footage calculator first if you only have room dimensions, to get your exact area. Then enter that area here along with your box coverage and waste allowance to convert it into the number of boxes to buy.