Measure the floor in square feet, add 10%, divide by the square feet printed on one box, and round up. A 200 sq ft room with boxes that cover 23.64 sq ft needs 200 × 1.10 ÷ 23.64 = 9.3, so 10 boxes. Use 15% instead of 10% for diagonal layouts, small rooms and rooms with closets or many doorways.
Boxes by area and box size
Vinyl plank boxes vary a lot in coverage, from under 20 to more than 30 sq ft, depending on plank size and thickness. Never assume: the coverage is printed on the end of every box and on the product page. With 10% waste:
| Floor area | With 10% waste | 18.7 sq ft box | 20.1 sq ft box | 23.64 sq ft box | 26.5 sq ft box |
|---|---|---|---|---|---|
| 100 sq ft | 110 | 6 | 6 | 5 | 5 |
| 150 sq ft | 165 | 9 | 9 | 7 | 7 |
| 200 sq ft | 220 | 12 | 11 | 10 | 9 |
| 300 sq ft | 330 | 18 | 17 | 14 | 13 |
| 500 sq ft | 550 | 30 | 28 | 24 | 21 |
| 800 sq ft | 880 | 48 | 44 | 38 | 34 |
The flooring calculator does this for any box size and adds cost and underlayment rolls.
Worked example: a living room and hallway
A living room is 18 × 14 ft. A hallway off it is 3.5 × 14 ft. The planks come 23.64 sq ft to a box at $2.49 per sq ft.
- Living room: 18 × 14 = 252 sq ft. With 10%: 277.2 sq ft ÷ 23.64 = 11.73 → 12 boxes.
- Hallway: 3.5 × 14 = 49 sq ft. A narrow hall is nearly all edge cuts, so use 15%: 56.35 ÷ 23.64 = 2.38 → 3 boxes.
- Total: 15 boxes. Treating both spaces as one 301 sq ft area at 10% gives the same 15 here. With other sizes the two methods can differ by a box. When the floor runs continuously from room to room, offcuts from one space get used in the other and the combined figure is fine; when the rooms are separate, count them separately.
- Cost: 12 boxes for the living room cover 283.68 sq ft × $2.49 = $706.36. You pay for whole boxes, not for the square footage of the room.
Box price vs square-foot price
Stores list vinyl plank by the square foot, but you buy it by the box. A box priced at $59.97 that holds 23.64 sq ft works out to $2.54 per sq ft. When comparing two products, divide box price by box coverage so you compare like with like; a cheaper-looking box may simply hold less.
Do you need underlayment?
Many vinyl plank products have a foam or cork pad attached to the back. Most of those say not to add another pad, because a soft layer under a click joint lets it flex and break. Products without a pad usually need a specific underlayment. The installation instructions tell you which, and following them matters for the warranty. If you do need it, underlayment comes in rolls, often 100 sq ft, and is laid without overlap, so divide the room area by the roll size and round up.
What else to buy
- Transition strips at each doorway where the floor meets another surface.
- Quarter round or new baseboard to cover the expansion gap, measured in linear feet around the room.
- A spare box. Keep one unopened box for repairs. Rigid core vinyl planks can be replaced individually, but only if you have a match from the same lot.
Common mistakes
- Using the room’s footprint from a listing. Measure the actual floor, wall to wall, including closets you’ll floor.
- Forgetting the waste allowance. Every row ends in a cut, and some planks arrive with damaged edges.
- Buying exactly the rounded-up count for several rooms separately and together. Pick one method. Counting each room separately, then adding, gives the safer number.