How Much Flooring Do I Need? Boxes by Room Size and Waste
Part of the project planner: Planning new floors and tile.
A room 15 × 12 ft (180 sq ft) needs 198 sq ft of flooring with 10% for waste, which is 10 boxes of 20 sq ft. The area is the length times the width, and the waste covers cuts at the walls and mistakes. The flooring calculator works it out for your own room, waste and box size, with a cost estimate.
Boxes of flooring by room size
Boxes of 20 sq ft, for three waste allowances:
| Room | Area | 5% waste | 10% waste | 15% waste |
|---|---|---|---|---|
| 10 × 10 ft | 100 sq ft | 6 boxes | 6 boxes | 6 boxes |
| 12 × 12 ft | 144 sq ft | 8 boxes | 8 boxes | 9 boxes |
| 12 × 15 ft | 180 sq ft | 10 boxes | 10 boxes | 11 boxes |
| 14 × 20 ft | 280 sq ft | 15 boxes | 16 boxes | 17 boxes |
| 16 × 24 ft | 384 sq ft | 21 boxes | 22 boxes | 23 boxes |
| 20 × 30 ft | 600 sq ft | 32 boxes | 33 boxes | 35 boxes |
How much waste to allow
For the 180 sq ft room:
| Waste | Layout | Flooring to buy | Boxes of 20 sq ft |
|---|---|---|---|
| 5% | Straight layout, simple room | 189 sq ft | 10 boxes |
| 7% | A typical room | 193 sq ft | 10 boxes |
| 10% | Diagonal layout or many cuts | 198 sq ft | 10 boxes |
| 15% | Herringbone or patterns | 207 sq ft | 11 boxes |
How to measure
- Measure the length and width of each room, and for an L-shape or an alcove, split it into rectangles and add them. See the square footage guide.
- Include closets and the area under appliances that you will move, but not the area under a permanent island or cabinets.
- Measure doorways and hallways, and add the area under the door.
- Round up each box, and add a spare box for repairs later.
Before you install
- Acclimate wood and laminate in the room for the time the maker says, usually 48 hours or more.
- Prepare the subfloor: it should be flat, clean and dry. Fill dips and sand high spots.
- Plan the layout: run planks along the longest wall or the main light, and avoid a thin row of boards at the last wall by starting from the center.
- Leave an expansion gap at the walls (usually about ½ inch), covered by the baseboard.
- Check the moisture: in a basement or on concrete, use a vapor barrier or a flooring made for it.
For laminate and vinyl plank with the underlayment and trim, see the laminate floor materials calculator, and for tile the tile calculator. Estimates only: confirm the quantities with your supplier.
Frequently asked questions
How much flooring do I need for a room?
The room area plus 5 to 10% for cuts and waste. A room 15 × 12 ft is 180 sq ft, so 198 sq ft with 10%, which is 10 boxes of 20 sq ft.
How much extra flooring should I buy?
5% for a straight layout in a simple room, 7 to 10% for a typical room, 10% or more for a diagonal layout and 15% for herringbone or a pattern. Buy a spare box for repairs.
How do I calculate boxes of flooring?
Divide the area you need (with waste) by the coverage of one box and round up. 198 sq ft ÷ 20 sq ft per box is 9.9, so 10 boxes.
Do I need to buy flooring from the same lot?
Yes, buy all the boxes at one time, so that the color and the finish match. Mix the planks from several boxes as you lay them.
Do I need underlayment?
Most laminate and floating floors need an underlayment (a pad) for sound, moisture and a smooth surface, unless it is already attached. Check the maker's instructions.
More guides
Tools & materials for this project
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.