Boxes of flooring for a 12 × 15 ft room
180 sq ft laid straight, with the default waste allowance for each material, at the median carton size and typical price.
| Material | Sq ft per box | Waste | Boxes | Price / sq ft | Material cost |
|---|---|---|---|---|---|
| Laminate | 19.1 | 10% | 11 | $1.89 | $397 |
| Luxury vinyl plank (LVP) | 19.6 | 10% | 11 | $2.39 | $515 |
| Engineered hardwood | 23.6 | 5% | 9 | $4.99 | $1,060 |
| Solid hardwood | 22 | 5% | 9 | $5.58 | $1,105 |
| Porcelain tile 12×24 | 15.6 | 10% | 13 | $3.58 | $726 |
| Ceramic tile 12×12 | 11 | 10% | 18 | $1.39 | $275 |
How the flooring calculator works
Floor area = Σ length × width
Area to buy = floor area × (1 + waste %)
Boxes = area to buy ÷ sq ft per box, rounded up
Cost = boxes × sq ft per box × price per sq ft
Example
A 12 × 15 ft room is 180 sq ft. With 10% waste you need 198 sq ft, and 198 ÷ 19.1 sq ft per box = 10.37, so 11 boxes of laminate.
Choosing a waste allowance
Every row ends with an offcut, and some boards arrive chipped or have defects you'll want to cull. Straight layouts in simple rooms waste the least; diagonal and herringbone patterns cut an angle at every wall. The defaults here follow manufacturer and retailer guidance: 5% for hardwood laid straight (Home Depot's hardwood guide), 10% for laminate, vinyl and tile (Pergo, clé), 15% for diagonal and 20% for herringbone (clé, Inch Calculator). Add a few percent for rooms with many corners, closets or a fireplace hearth.
Not included
Underlayment, moisture barrier, thinset and grout, transitions and trim are sold separately; see the product's installation instructions for what it requires.
Frequently asked questions
How many boxes of flooring do I need?
Multiply length × width for each room, add the rooms together, add your waste allowance and divide by the square feet in one box, rounding up. A 12 × 15 ft room is 180 sq ft; with 10% waste that is 198 sq ft, and at 19.1 sq ft per box of laminate you need 11 boxes.
How much extra flooring should I buy?
For planks and tile laid straight, 10% is the usual allowance: Pergo and tile retailer clé both recommend it. Home Depot's hardwood guide uses a 5% cutting allowance plus up to 10% more on a diagonal. clé suggests about 15% for diagonal tile, and Inch Calculator uses 20% for diagonal, herringbone or parquet patterns.
How many square feet are in a box of flooring?
It varies by product, so always check the carton. In the Home Depot listings we reviewed, laminate ran 13.74–24.2 sq ft per box, vinyl plank 18–23.95, engineered hardwood 19.7–42.9 and 12×24 porcelain tile 14–17.6.
How much does flooring cost per square foot?
Material-only prices at a big-box store in 2026 ranged roughly from $0.99–$2.79 per sq ft for laminate, $1.49–$3.29 for vinyl plank, $2.99–$6.99 for engineered hardwood and $4.79–$6.38 for solid hardwood in the listings we checked; designer lines and cost-guide ranges go much higher. Installation, underlayment and trim are extra.
Should I keep leftover flooring?
Yes — keep at least one unopened box. Colors and textures change between production runs, so matching boards or tiles years later for a repair can be difficult. Leftover full boxes can often be returned, so check the store's return policy before you buy.
Sources
Prices are national shelf prices and cost-guide ranges read on September 17, 2026. The calculator uses the typical price (the median of the shelf prices we saw) and shows the low–high range; type your own local price to update the total.
All sources for this page (12)
Coverage, yield and building specs
- The Home Depot — How to install hardwood flooring accessed 2026-09-16
- Pergo — Project checklist accessed 2026-09-16
- clé tile — How much extra tile to buy accessed 2026-09-16
- Inch Calculator — Flooring calculator accessed 2026-09-16
Prices
- The Home Depot — Laminate wood flooring accessed 2026-09-16
- HomeGuide — Flooring installation cost accessed 2026-09-16
- The Home Depot — Vinyl plank flooring accessed 2026-09-16
- The Home Depot — Engineered hardwood accessed 2026-09-16
- The Home Depot — Bruce 3/4 in. solid hardwood accessed 2026-09-16
- The Home Depot — 12x24 porcelain tile accessed 2026-09-16
- Floor & Decor — 12 x 24 tile accessed 2026-09-16
- The Home Depot — 12x12 ceramic tile accessed 2026-09-16
Estimates for planning purposes only, not professional construction advice. Check local building codes and your product's instructions before you build. Prices are national averages collected from public retail listings and cost guides and will differ in your area. BuildHowMuch is independent and not affiliated with, endorsed by or paid by any retailer or manufacturer mentioned on this page. Nothing you enter is stored or sent anywhere.