Flooring calculator
Enter the size of each room and the coverage of a box to see how many square feet to buy and how many boxes that is, with extra for cuts.
This answer is for the example values in the boxes above. 14 by 12 ft and 6 by 5 ft, 10% extra, boxes of 24 square feet. Change the boxes to see your own answer.
Boxes are bought whole, so the floor in the boxes is a little more than the floor that is needed.
How it works
The calculator adds the area of up to three rooms, each the length times the width in feet. It adds the extra you choose, divides by the square feet in one box and rounds up to whole boxes. A room with a second part is two rooms.
Boxes are bought whole, so the floor in the boxes is a little more than the floor that is needed. The calculator shows the difference.
A worked example
Rooms of 14 by 12 feet and 6 by 5 feet are 168 and 30 square feet, 198 together. With 10 percent extra that is 217.8 square feet. A box covers 24 square feet, and 217.8 divided by 24 is 9.075, so you buy 10 boxes. They hold 240 square feet, which is 42 more than the rooms need. At $3.49 a square foot the boxes cost $837.60.
A single room of 15 by 12 feet is 180 square feet. With 8 percent extra it is 194.4, and boxes of 20 square feet make 10 boxes.
How much extra
One maker of hardwood flooring advises buying at least 10% more than you need, in case the installer damages some. The calculator starts at 10 percent, and you can set the figure from 0 to 100. The starting value is the calculator’s own, and your flooring maker’s guide comes first.
The cost
If the flooring is sold by the box, the cost is the floor in the whole boxes times the price of a square foot. If you leave the coverage of a box empty, the page gives the square feet to buy, and the cost is that area times the price.
What it leaves out
The rooms are rectangles. The calculator does not know the pattern of the floor or the width of the planks, so set the extra for your layout. It does not count underlayment, trim or the floor under cabinets.
Sources
- Bruce, Hardwood Flooring Checklist: be ready before you buy, read on 2026-11-02.
Questions
How much flooring do I need?
Add the area of the rooms and add some extra. Rooms of 14 by 12 feet and 6 by 5 feet are 198 square feet, and 217.8 with 10% extra.
How many boxes of flooring do I need?
Divide the area with its extra by the square feet in a box, printed on the box, and round up. 217.8 square feet in boxes of 24 is 9.075, so 10 boxes.
How much extra flooring should I buy?
One maker of hardwood flooring advises buying at least 10% more than you need, in case the installer damages some. The calculator starts at 10%, and your flooring maker’s guide comes first.
Why does the cost use whole boxes?
Boxes are sold whole, so you pay for the floor in all of them. 10 boxes of 24 square feet hold 240 square feet, and at $3.49 a square foot that is $837.60.
How do I enter a room that is not a rectangle?
Split it into rectangles and enter each one as a room. The calculator adds their areas, and it has a place for three.
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