How much flooring do I need?
Measure the floor from wall to wall at its longest and widest, and find the square feet per box printed on the box or the product page: it differs from one floor to the next. Got the area already? Choose "Square feet" and type it in.
Some boards get cut at the ends of rows and around doorways, so buy a little more than the floor. Quick-Step and the National Wood Flooring Association both say add 5% for a regular room, which is where the calculator starts.
Source Quick-Step · How much floor do I need for my room? ↗Wood Floor Business · "Coming up short", answered by the National Wood Flooring Association (2011) ↗
How to calculate flooring
Here it is with your numbers:
- Multiply the length by the width: 12 × 10 = 120 sq ft.
- Add 5% for waste: 120 × 1.05 = 126 sq ft.
- Divide by the square feet in a box: 126 ÷ 20 = 6.3 boxes.
- Round up to whole boxes: 7 boxes, which hold 7 × 20 = 140 sq ft.
It means buying 7 boxes of flooring: 140 sq ft for a 120 sq ft floor.
Flooring is sold by the box, so always round up. What's left over is worth keeping: Mannington recommends holding on to extra material for repairs later.
Source Common Core State Standards · Grade 3, area of rectangles (3.MD.C.7) ↗Mannington · What to expect from your floor installation (waste factor) ↗
How much extra flooring to buy for waste
More cuts mean more waste. Use the figure for your job, or the one in your flooring's installation guide.
| Job | Extra |
|---|---|
| Regular room (Quick-Step), wood No. 1 grade or better (NWFA) | 5% |
| Wood plank, shorts or lower grades (NWFA) | 7 – 10% |
| Room with many angles or curves (Quick-Step) | 10% |
| Diagonal layout or irregular room (NWFA) | 10% or more |
Mannington adds a waste factor of 5 – 15% to orders, depending on the product.
Flooring for common room sizes
With 5% extra for waste, in boxes of 20 sq ft.
| Room | With waste | Boxes |
|---|---|---|
| 10 × 10 ft | 105 sq ft | 6 |
| 12 × 10 ft | 126 sq ft | 7 |
| 12 × 12 ft | 151.2 sq ft | 8 |
| 14 × 12 ft | 176.4 sq ft | 9 |
| 16 × 14 ft | 235.2 sq ft | 12 |
| 20 × 15 ft | 315 sq ft | 16 |
| 24 × 20 ft | 504 sq ft | 26 |
FAQs
How do you calculate square feet for flooring?
Measure the room's length and width in feet and multiply them: a 12 × 10 ft room is 120 sq ft. Add the extra for waste (5% makes it 126 sq ft), then divide by the square feet on the box and round up. Split an L-shaped room into rectangles and add them.
Source Common Core State Standards · Grade 3, area of rectangles (3.MD.C.7) ↗
How do you install laminate flooring?
Pergo's guide starts with letting the unopened boxes acclimatize in the room for 48 hours before you lay them (59 – 77 °F). The floor floats, so leave an expansion gap of at least 8 mm (about 5/16 in) at every wall, pipe and doorframe, and never fix it down. Keep one box label and a few spare boards.
Source Pergo · Installation guide, laminate flooring (version 07.2026) ↗
How do you install vinyl plank flooring?
For Pergo's rigid click vinyl, acclimatize the unopened boxes for 48 hours in the room, on a flat, solid, dry subfloor. It also floats, so leave an 8 mm (about 5/16 in) expansion gap around the whole edge and around pipes and anything fixed. Pergo recommends keeping some spare panels for repairs.
Source Pergo · Installation guide, rigid click vinyl (version 07.2026) ↗
Sources
- Quick-Step: How much floor do I need for my room?
- Wood Floor Business: "Coming up short", answered by the National Wood Flooring Association (2011)
- Mannington: What to expect from your floor installation (waste factor)
- Pergo: Installation guide, laminate flooring (version 07.2026)
- Pergo: Installation guide, rigid click vinyl (version 07.2026)
- Common Core State Standards: Grade 3, area of rectangles (3.MD.C.7)