RightFiguresWhole boxes for one room
Room area is length times width. The waste percent you enter scales that area. The box count is how many boxes cover the scaled area when each box covers the amount you enter. The count is a whole number because a partial box is still a box you buy.
NIST Appendix B defines the international foot used for the room. Loudoun County’s Construction Task Catalog gives carpet, VCT, and concrete as examples of materials sold in standard sizes, and it says that catalog’s unit prices include a waste allowance. This page does not use that allowance. You enter both the waste percent and the coverage of one box.
This is not the concrete calculator or the paint calculator. It does not count individual planks, and it does not price the flooring.
12 feet by 10 feet
12.00 feet by 10.00 feet with 10% waste needs 132.00 square feet. At 20.00 square feet per box, that is 7 boxes. Those boxes cover 140.00 square feet, so 8.00 square feet remain. Enter 0 when you are not adding waste. A blank field is not zero.
10.00 feet by 10.00 feet, 0% waste, and 25.00 square feet per box need 100.00 square feet. That is 4 boxes exactly, and 0.00 square feet remain. The ceiling does not add a fifth box.
The displayed area is not the box count
25.01 feet by 0.40 feet is exactly 10.004 square feet. Rounded half up, the area displays as 10.00 square feet. Dividing that displayed area by 10.00 square feet per box would suggest 1 box. The exact area still needs 2 boxes. The leftover exact area is 9.996 square feet, which displays as 10.00 square feet.
Above 1,000,000 boxes
A 1,000.00 by 1,000.00 foot room at 100% waste and 0.01 square feet per box is above 1,000,000 boxes. No count is shown. A 100.00 by 100.00 foot room, 0% waste, and 0.01 square feet per box is exactly 1,000,000 boxes, and that count is shown. Those boxes cover the 10,000.00 square feet exactly.
Frequently asked questions
Does this page plan the plank or tile layout?
No. A box is only the coverage you enter. The direction of the boards, the
pattern, and the cuts at the walls are not calculated.
Should I add the waste that is already in a catalog price?
This page does not look up a catalog. If the coverage or the price you are
using already includes waste, enter 0 here unless you want more. The percent
you enter is added to the room area.
Are the room dimensions sent to analytics?
No. Analytics may record that this calculator ran. Dimensions, waste,
coverage, and the box count stay in this browser.
Sources & review
- Guide to the SI, Appendix B — National Institute of Standards and Technology
- Using the Construction Task Catalog — Loudoun County
Last reviewed: . The formula is reproduced above so you can check the math independently.
Educational estimate only. This page does not plan the layout or price the flooring.