Use this flooring calculator to find how many boxes of flooring you need. Add one or more rooms, choose LVP, laminate, hardwood or carpet, and pick your layout. You get the boxes, underlayment and trim to buy, and a cost estimate if you add your prices.
Extra and cost
Set by the layout. You can change it.
Box coverage varies by product, so enter the figure printed on the box. Closets count as floor too.
How the flooring calculator works
- Floor area = length × width of each room, added together
- Area to buy = floor area × (1 + extra): 10% for a straight layout, 15% for diagonal and 20% for herringbone
- Boxes = area to buy ÷ coverage per box, rounded up
- Underlayment = floor area ÷ 100, rounded up to 100 sq ft rolls
- Trim = the outside edge of every room, minus 3 ft for each doorway
- Carpet = area to buy ÷ 9, in square yards, with pad for the floor area
Worked example
A 14 × 12 ft bedroom in luxury vinyl plank, laid straight, with boxes of 20 sq ft and one doorway:
- Floor area: 14 × 12 = 168 sq ft
- Area to buy: 168 × 1.10 = 184.8 sq ft
- Boxes: 184.8 ÷ 20 = 9.2, rounded up to 10 boxes (200 sq ft)
- Underlayment: 168 ÷ 100 = 1.7, so 2 rolls
- Trim: 2 × (14 + 12) = 52 ft, minus 3 ft for the door = 49 ft
Add a 10 × 10 ft hallway area and the total is 268 sq ft, or 15 boxes. In carpet, the same two rooms take 268 × 1.10 ÷ 9 = 32.8 sq yd.
Boxes for common rooms
For boxes of 20 sq ft:
| Room | Floor area | Straight (10%) | Herringbone (20%) | Carpet, sq yd (10%) |
|---|---|---|---|---|
| 10 × 10 ft | 100 sq ft | 6 boxes | 6 boxes | 12.2 |
| 12 × 12 ft | 144 sq ft | 8 boxes | 9 boxes | 17.6 |
| 14 × 12 ft | 168 sq ft | 10 boxes | 11 boxes | 20.5 |
| 16 × 14 ft | 224 sq ft | 13 boxes | 14 boxes | 27.4 |
| 20 × 16 ft | 320 sq ft | 18 boxes | 20 boxes | 39.1 |
Flooring types at a glance
| Flooring | Sold by | Underneath |
|---|---|---|
| Luxury vinyl plank (LVP) | Boxes, often 18 to 25 sq ft | Underlayment, unless a pad is attached |
| Laminate | Boxes, often 15 to 25 sq ft | Foam underlayment, with a vapor barrier over concrete |
| Engineered hardwood | Boxes, often 20 to 30 sq ft | Underlayment for floating floors |
| Solid hardwood | Boxes or bundles, about 20 sq ft | Floor paper or felt over the subfloor |
| Carpet | Square yards, from 12 ft wide rolls | Carpet pad |
Tips for a new floor
- Let LVP, laminate and wood sit in the room for a day or two before you install, so they adjust to the temperature and humidity.
- Leave the expansion gap the maker asks for at the walls, usually ¼ to ½ in, and cover it with baseboard or quarter round.
- Run planks along the longest wall, or toward the main window, so the room looks longer.
- Mix planks from several boxes as you go, so color and grain stay even.
- Check that the subfloor is flat. Most floating floors need it within about 3/16 in over 10 ft, so check the maker’s guide.
- For a tiled floor instead, the tile calculator counts tiles and boxes. The square footage calculator helps with odd-shaped rooms.
Frequently asked questions
How much flooring do I need?
Multiply each room’s length by its width and add the rooms together. Then add 10% for a straight layout, or more for diagonal and herringbone. Divide by the coverage on the box and round up. A 14 × 12 ft room needs about 185 sq ft, or 10 boxes of 20 sq ft.
How much extra flooring should I buy?
About 10% for a straight layout in a simple room, 15% for diagonal and 20% for herringbone or rooms with many corners. Keep one spare box after the job for repairs.
How many square feet are in a box of flooring?
It depends on the product. LVP and laminate boxes often hold 18 to 25 sq ft, and engineered hardwood 20 to 30 sq ft. The exact figure is printed on the box.
How do I calculate carpet?
Carpet is sold by the square yard. Multiply the room area in square feet by 1.10 for seams and fitting, then divide by 9. A 12 × 12 ft room needs about 17.6 sq yd. Carpet comes in 12 ft wide rolls, so rooms wider than 12 ft need a seam.
How much does it cost to install flooring?
It depends on the flooring, the underlayment, labor and removing the old floor, and prices vary a lot by region. Enter your prices per sq ft, or per sq yd for carpet, to get a total.
Results are estimates for planning. Box coverage and waste vary, so confirm with your supplier. See How We Calculate for the formulas we use.
Guides for this project
Flooring & TileHow to Clean Laminate and Vinyl Plank (LVP) Floors: What to Use and AvoidTo clean laminate floors, sweep or vacuum first, then wipe the floor with a microfiber mop that is…Read the guide →10 min read
Flooring & TileLVP vs Laminate Flooring: Which Is Better?LVP (luxury vinyl plank) is the better choice for wet areas such as bathrooms, kitchens, laundry rooms and…Read the guide →9 min read