Square footage for flooring
Measure the floor, add the right waste allowance, turn it into boxes — for laminate, vinyl plank, hardwood or tile.
Step 1: measure the floor
Floor area is simply length × width, measured wall to wall (under any trim that is coming off). A 12 × 14 ft room is 168 sq ft. In metres, a 3.6 × 4.2 m room is 15.1 m².
Odd shapes
- L-shaped rooms: split into two rectangles, calculate each, add them.
- Closets and doorways getting the same floor: add them as extra pieces.
- Islands, hearths, fixed units: subtract each as its own length × width — these are the only deductions that matter for flooring.
Step 2: add a waste allowance
You always buy more than the bare floor area, to cover cuts and offcuts you cannot reuse, plus a little for future repairs:
| Situation | Typical allowance |
|---|---|
| Straight lay, simple rectangle | 10% |
| Diagonal lay | 15% |
| Herringbone / chevron, or grain matching | 15–20%+ |
| Lots of jogs, closets, angles | 15% |
These are planning starting points, not guarantees. Your installer or the manufacturer may recommend a different figure for a specific product.
Step 3: turn it into boxes
area to buy = floor area × (1 + waste %)
boxes = round up (area to buy ÷ coverage per box)
Worked example — 168 sq ft floor, 10% waste, boxes of 23.77 sq ft:
- 168 × 1.10 = 184.8 sq ft to buy
- 184.8 ÷ 23.77 = 7.8 → 8 boxes (190.2 sq ft purchased)
It works the same for every product
Laminate, luxury vinyl plank (LVP), engineered hardwood and tile are all sold by the box and estimated the same way — only the coverage per box changes, and that is printed on the box. Box coverage varies even within one product line, so use the number on the box you are actually buying.
| Product | Coverage per box (varies) |
|---|---|
| Luxury vinyl plank (LVP) | 18–24 sq ft |
| Laminate | 18–24 sq ft · 1.5–2.5 m² |
| Engineered hardwood | 15–30 sq ft |
| Tile | 8–15 sq ft |
Put your own box coverage into the flooring calculator and it gives you the boxes and the leftover. Underlayment and trim are separate purchases with their own rules — add them as manual items in the room planner.
Questions
How do I calculate square footage for flooring?
Measure the room length and width in feet and multiply them. A 12 × 14 ft room is 168 sq ft. For an L-shaped room, split it into rectangles, work out each, and add them up. Then add a waste allowance before you buy — see below.
How much extra flooring should I buy?
For a straight lay in a simple rectangular room, add about 10%. For diagonal or herringbone layouts, patterned planks that need matching, or rooms with lots of jogs and closets, 15% or more is safer. The allowance covers cuts, mistakes, and future repairs.
How many boxes of flooring is that?
Divide your area-plus-waste by the coverage printed on the box, then round up. 168 sq ft + 10% = 184.8 sq ft; at 23.77 sq ft per box that is 7.8 → 8 boxes. The flooring calculator does this for any box size.
Do doors and windows reduce the flooring area?
No. Flooring is about the floor, so wall openings never change it. Only things the floor will not go under — a built-in island, a hearth, a fixed cabinet run — are subtracted, as their own length × width.
Is floor area the same as the paint or drywall area?
No. Floor area is length × width. Wall area is the perimeter times the wall height, which is much larger. Do not use one for the other — see floor area vs paintable area.