How much flooring do I need for a 15×20 room?
A 15 × 20 ft room is 300 square feet. With 10 percent for cuts you need 330 square feet of flooring, which is 17 boxes at 20 square feet per box or 14 boxes at 24. Add 3 rolls of 100 square foot underlayment if the flooring does not have a pad attached.
Boxes of flooring for a 15×20 room
| Sq ft per box | Boxes to buy (10% waste) | Sq ft in those boxes | Leftover |
|---|---|---|---|
| 18 sq ft | 19 | 342 | 42 sq ft |
| 20 sq ft | 17 | 340 | 40 sq ft |
| 24 sq ft | 14 | 336 | 36 sq ft |
| 30 sq ft | 11 | 330 | 30 sq ft |
The room is 300 square feet; with 10 percent waste you need 330 square feet of flooring. Box coverage is printed on the carton and ranges from about 17 to 30 square feet for plank products.
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What flooring for a 15×20 room costs
| Flooring | Material per sq ft | For 330 sq ft | Installed, typical |
|---|---|---|---|
| Laminate | $1.50 to $4 | $495 to $1,320 | $1,200 to $2,400 |
| Luxury vinyl plank | $2.50 to $6 | $825 to $1,980 | $1,500 to $3,000 |
| Engineered hardwood | $4 to $9 | $1,320 to $2,970 | $2,400 to $4,200 |
| Solid hardwood | $5 to $12 | $1,650 to $3,960 | $3,000 to $5,400 |
| Tile | $2 to $8 | see the tile calculator | $3,000 to $6,000 |
Underlayment adds about 30 to 60 cents per square foot, and transition strips run $15 to $40 per doorway. Removing old carpet or tile and disposing of it is extra.
Laying out a 15×20 floor
- Run planks parallel to the longest wall or the main light source; in this room that is the 20 ft direction.
- Check the last row before you start: 0.0 in would be left over if you used full 7.5 in planks across the 20 ft width, so split the difference between the first and last rows if it comes out under 2 in.
- Leave a 1/4 to 3/8 in expansion gap at every wall; the baseboard covers it.
- Diagonal or herringbone layouts need 15 percent waste: 345 square feet instead of 330.
- Let the boxes sit in the room for 48 hours before installing so the planks acclimate.
Common questions
How many boxes of flooring for a 15x20 room?
17 boxes at 20 square feet per box, 14 at 24, or 11 at 30, to cover 300 square feet with 10 percent waste. Check the carton for its exact coverage.
How many square feet of flooring for a 15x20 room?
300 square feet of floor, so buy 330 square feet with 10 percent waste or 345 with 15 percent for a diagonal pattern or a room with closets and angles.
How much underlayment for a 15x20 room?
3 rolls of 100 square foot underlayment for 300 square feet, unless the planks have a pad attached. Over concrete, use underlayment with a vapor barrier.