How to calculate flooring boxes
Multiply room length by width to get floor area. Add the waste allowance for cuts and layout, divide by coverage per box, then round up. Material cost uses the full-box coverage purchased. Labor cost, if entered, uses the original floor area.
Boxes = round up [length × width × (1 + waste ÷ 100) ÷ square feet per box]
A 12 × 10 room: worked example
A 120-square-foot room with 10% waste needs 132 square feet of flooring. At 20 square feet per box, buy 7 boxes covering 140 square feet. At the sample material price of $3 per square foot, materials cost $420. If labor is $2 per square foot of room area, labor adds $240, for a $660 estimate before tax and other work.
How much extra flooring should you buy?
The default 10% is a starting assumption, not a universal requirement. Straight layouts, diagonal cuts, patterned products and irregular rooms can have different needs. Use your manufacturer’s instructions and your installer’s layout plan. An installation guide for one Home Decorators Collection product calls for 5% extra, or 10% for diagonal work; do not apply that requirement to every flooring product.
Source: Manufacturer installation instructions hosted by The Home Depot (PDF).
What this budget leaves out
Underlayment, subfloor repairs, demolition, disposal, trim, transitions, stairs, delivery and tax are separate. The sample unit prices are examples, not local market quotes. Enter current prices for your selected product and installer.
Flooring calculator FAQs
Is the price per box or per square foot?
This tool uses price per square foot. If a box costs $60 and covers 20 square feet, enter $3. The estimate charges for all square footage in the whole boxes you need to buy.
How do I handle an L-shaped room?
Divide it into non-overlapping rectangles and add their areas. For this single-rectangle tool, you can enter the total area as length and 1 as width, with both fields in feet; that preserves the area calculation. Review cuts and waste separately.
Can I use this for vinyl, laminate or hardwood?
Yes, when the product is sold in boxes with a stated square-foot coverage. Enter the actual coverage and installation allowance for your product. This does not calculate a tile layout, grout or adhesive.