Flooring Calculator
Find out how many square feet and how many boxes of flooring to buy, including waste.
| Item | Amount |
|---|---|
| Boxes | |
| Left over | |
| Estimated cost |
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How the flooring calculator works
Multiply length by width for each room and add the areas together. Subtract anything you will not cover, then add a waste percentage for cuts, mistakes and unusable pieces. If you enter the coverage printed on the box, the calculator rounds up to whole boxes, since flooring is sold by the box.
Worked example: two rooms with a kitchen island
A 12 ft x 14 ft room is 168 sq ft and a 10 ft x 10 ft room is 100 sq ft, for 268 sq ft. Subtract a 20 sq ft island and you have 248 sq ft. Hardwood in a straight layout takes about 10% extra, so you need 272.8 sq ft. With 20 sq ft boxes that is 14 boxes, or 280 sq ft, leaving about 32 sq ft spare. At $4.50 per sq ft the flooring costs about $1,260.
Typical extra to order
| Flooring | Straight | Diagonal or herringbone |
|---|---|---|
| Hardwood | 10% | 15% |
| Laminate | 7% | 12% |
| Luxury vinyl plank or tile | 7% | 10% |
| Ceramic or porcelain tile | 10% | 15% |
These are common installer starting points. Small mosaic tile and natural stone often need more, roughly 12% to 20%. Rooms with many corners, closets or angles also need extra.
Frequently asked questions
How much extra flooring should I buy?
About 7 to 10 percent for laminate and vinyl plank, 10 percent for hardwood and tile in a straight layout, and 10 to 15 percent or more for diagonal or herringbone patterns.
How do I measure an oddly shaped room?
Split it into rectangles, measure each one, and add each as its own room in the calculator.
Should I keep leftover flooring?
Yes. A few spare pieces or a box from the same batch lets you make matching repairs later. Store it somewhere dry and write the batch number on the carton.
Why do I round up to whole boxes?
Flooring is sold in full boxes, and a box from a different batch can differ slightly in color. Buy the whole amount at once.
Estimates only. Confirm quantities with your installer or supplier. Tiling a wall, shower or backsplash, or need grout and thinset? Use the tile calculator.