How Much Extra Flooring Should I Buy?
For most rooms with a straight layout, adding 5 to 10 percent to the floor area is a common allowance. Diagonal and herringbone layouts, and rooms with many corners, need more.
Why you need extra at all
Flooring is cut to fit at walls, around doorways and into corners, and the offcuts often cannot be reused. Some boards or tiles will also be damaged, have defects, or turn out to be the wrong shade for the spot. An allowance covers this, so you do not run out partway through the job.
Common waste allowances
Flooring guides give these ranges. They differ between sources, so use them as starting points and ask your installer or supplier what they use.
| Flooring | Straight layout | Diagonal, herringbone or chevron |
|---|---|---|
| Laminate | about 5 to 8% | about 12 to 14% |
| Luxury vinyl plank or tile | about 7 to 10% | about 10 to 12% |
| Engineered hardwood | about 7 to 10% | about 12 to 15% |
| Solid hardwood | about 10% | about 15 to 17% |
| Large-format tile (12 inches or more) | about 10% | about 15% |
| Natural stone tile | about 15 to 20% | toward the high end |
Some guides suggest even more for intricate patterns such as herringbone, often 20 percent or above. Ask the person doing the work.
What pushes the figure up
- Angled layouts. Cuts at an angle waste more than cuts square to the wall.
- Many corners and alcoves. Every extra cut adds waste.
- Patterns and grain matching. Boards chosen to match color or grain mean more rejects.
- Large tiles. A bigger tile wastes more per cut.
- Your own experience. A first-time installer will usually waste more than a professional.
How whole boxes change the answer
Flooring is sold by the box, so you always buy a little more than the allowance. Take a room of 200 square feet, with boxes that cover 20 square feet:
| Allowance | Area to cover | Boxes to buy |
|---|---|---|
| 5% | 210 sq ft | 11 |
| 10% | 220 sq ft | 11 |
| 15% | 230 sq ft | 12 |
| 20% | 240 sq ft | 12 |
Notice that 5 and 10 percent both need 11 boxes, and 15 and 20 percent both need 12, because of the rounding. At 10 percent the 11 boxes are an exact fit with nothing to spare, so if you are close to a whole box it is worth checking the exact figure. The calculator shows it, and how much is left over.
Keeping spares
Many installers suggest keeping a few spare planks or tiles for future repairs, because the same product may not be available later, and different batches can vary slightly. Ask your supplier whether you should buy everything from the same batch in one go, and check each box before you open it.
How to measure
Measure each room's length and width, and include closets and hallways that the flooring will run into. Floor under permanent cabinets is usually left uncovered. Split odd shapes into rectangles. The guide to measuring an area covers circles, triangles and L-shapes.
The flooring calculator adds the waste allowance and rounds up to whole boxes for you.
Related
Questions
Is 10 percent enough for any floor?
It is a common figure for a straight layout in a simple room. Diagonal and herringbone layouts, rooms with lots of corners, and natural stone usually need more. Ask your installer what they use for your layout.
Do I add the waste before or after dividing by the box size?
Before. Add the allowance to the floor area first, then divide by the coverage of one box, then round up to a whole box. The flooring calculator follows that order.
What if the answer is only just over a whole box?
You still need to round up, so a result of 11.2 boxes means 12. The leftover is useful as spare material for future repairs, and the calculator shows how much it is.
Can I return unopened boxes?
It depends on the store or supplier. Ask about their return policy before you buy, and keep boxes sealed and undamaged until you are sure you will not need them.