How to Calculate Boxes of Flooring: Measure and Add Waste
To calculate how many boxes of flooring you need, measure the length and width of each area, multiply to get square footage, add 10 percent for waste, and divide by the square feet per box printed on the carton. Round up to the next whole box. For diagonal layouts, rooms with many corners, or discontinued flooring that cannot be reordered, add 15 percent or more.
What you need
- A 25 ft tape measure or a laser distance measurer
- Graph paper or a phone notes app for a rough floor plan
- A calculator
- The coverage per box from the carton label or product listing
Step 1: Sketch the floor plan
Draw the room, including closets, hallways and alcoves that will receive the same flooring. Break irregular shapes into rectangles. An L-shaped room, for example, becomes two rectangles measured separately.
Step 2: Measure each rectangle
Measure wall to wall at the widest points, in feet and inches. Convert inches to decimal feet by dividing by 12, so 14 ft 6 in becomes 14.5 ft. Measure into door openings and closets up to where the flooring will stop under the transition strip.
Step 3: Calculate square footage
Multiply length by width for each rectangle and add the results. A 12 ft by 14.5 ft room is 174 square feet. For an L-shaped room measuring 12 by 10 ft in one part and 8 by 6 ft in the other, the total is 120 plus 48, or 168 square feet. Do not subtract space for cabinets or furniture that sits on the floor unless it is permanently built in.
Step 4: Add a waste allowance
Cuts at walls, damaged planks in the box and pattern matching all use extra material. Use the following as a guide.
| Layout | Waste allowance |
|---|---|
| Simple rectangular room, straight lay | 5 to 10 percent |
| Rooms with closets, angles or many doorways | 10 to 15 percent |
| Diagonal or herringbone layout | 15 to 20 percent |
| Discontinued product, no reorder possible | Add 1 or 2 boxes on top |
For the 174 square foot room, a 10 percent allowance gives 191.4 square feet.
Step 5: Divide by the coverage per box
Coverage varies widely by product, from under 15 to more than 30 square feet per box. Divide the total by the coverage and round up. With a product covering 23.4 square feet per box, 191.4 divided by 23.4 is 8.18, so buy 9 boxes.
Finishing a room with a discontinued floor
When a project runs short with a discontinued product, measure only the remaining area. Count the full planks left over and multiply by the area of one plank (length times width in inches, divided by 144) to see how much is already on hand. Subtract that from the remaining square footage to find the shortfall. Leftover boxes are often sold in small lots, so knowing the exact number avoids paying for more than needed. The guide to discontinued Home Depot flooring covers where those lots appear.
Common mistakes
- Using the room’s listed size from a floor plan rather than measuring. Plans often round down.
- Forgetting closets, the area under a range or dishwasher, and stair landings.
- Rounding down when the result is just over a whole box.
- Buying from several dye lots. Boxes from one production run match better.
- Returning all extra boxes. Keeping one or two allows future repairs without hunting for a match.
Tips
Buy all boxes at the same time and open several before installing, mixing planks from different cartons as you go so color variation spreads evenly. Write the coverage, model number and dye lot from the carton in a notes file and photograph the label. Model numbers should be recorded as plain text exactly as printed. When planks may be salvaged later, such as from a closet, include that area in the measurements; see how to reuse closet flooring planks for that method.
Frequently asked questions
How many square feet are in a box of laminate flooring?
It depends on plank size and thickness. Thicker 12 mm laminate often covers less per box than 8 mm laminate. The exact figure is printed on the carton and the product page.
Should I buy 10 percent extra flooring?
Ten percent is the common rule for straight installations. Use more for diagonal patterns, complex rooms, or products that might be discontinued before a future repair.
Can I return unopened boxes of flooring?
Most retailers accept unopened boxes within their return period, but clearance and discontinued items may be final sale. Check the receipt before buying extra.
Photo: Clint__Budd, CC BY (CC BY 2.0 license), via Openverse.
More how-to guides: See all of our discontinued flooring how-to guides.
