Key takeaways
- Boxes = floor area × (1 + waste) ÷ coverage per box, rounded up.
- Waste percentages are rules of thumb, as we found no primary standard.
- Follow your product's instructions over any general figure.
Enter your room size and the coverage printed on the box. Add closets, hallways and other areas in "Other areas".
How the calculator works
- Area: length × width + other areas
- Order area: area × (1 + waste %)
- Boxes: order area ÷ coverage per box, rounded up
Worked example
A 12 × 15 foot room with 10% waste, using boxes that cover 20 square feet:
- Area: 180 square feet
- Order area: 198 square feet
- Boxes: 198 ÷ 20 = 9.9, so 10 boxes, or 200 square feet
Choosing a waste figure
We didn't find a primary published waste figure. These come from consumer guides, so treat them as starting points:
| Job | Common allowance |
|---|---|
| Small, simple space | About 5% |
| Straight run in an ordinary room | About 10% |
| Complicated job or several rooms | About 15% |
Each extra 5% is only a small change on paper, but a shortage is harder to fix. Flooring from a later batch can look different, and products get discontinued, so order enough at once. Ask your supplier whether it takes back unopened boxes.
| Waste on 180 sq ft | Order area | Boxes at 20 sq ft |
|---|---|---|
| 5% | 189 sq ft | 10 |
| 10% | 198 sq ft | 10 |
| 15% | 207 sq ft | 11 |
| 20% | 216 sq ft | 11 |
Measuring an irregular room
Split the floor into rectangles, work out each one, and add them. Measure into door openings where the flooring continues. For closets, add the area in "Other areas". A sketch with the measurements on it is worth bringing to the store.
Before you remove the old floor
Old vinyl tile, sheet flooring backing and adhesive can contain asbestos. Read about old flooring before you sand, scrape or pull anything up.
Frequently asked questions
Do I add waste before or after rounding to boxes?
Before. Add the allowance to the area, then round up to whole boxes.
How much extra flooring should I order?
There's no single standard. Consumer guides commonly use about 10% for a straight run and more for complex rooms. Your product's instructions come first.
What's wet-area or moisture guidance for wood floors?
We haven't included it here, because we couldn't read the National Wood Flooring Association's text directly. Follow your product's installation instructions.
Sources
We use primary sources where we can: building codes, federal rules and manufacturer documents. Read our editorial standards.
- Hunker: The 10 percent flooring guideline (a rule of thumb, not a standard)