Understanding your result
The headline is the boxes to buy, with the floor area, the planks and the spare beside it. The table shows the plank size and its area, the waste allowance, the area to order, the boxes, what they cover and the spare, the approximate number of planks, and the underlayment.
The input that moves the answer most is coverage per box. Two LVP products in the same plank size can differ by a quarter in box coverage, because one packs 8 planks and another 11. The planks figure is the box coverage divided by the area of one plank, times the boxes; if it does not match the plank count on the label, the note says so, and usually one of the two figures you typed is a nominal size.
The waste comes from the layout and the pattern repeat. Printed vinyl repeats a small number of face images; laying two identical planks side by side looks artificial, and the 5% is for the planks you set aside to avoid it. The same box arithmetic with no pattern question is on the laminate calculator; the general version for any boxed flooring is the boxes and cartons calculator. For vinyl tile rather than plank, use the LVT and peel-and-stick calculator.
How we calculate this
The waste figures are the layout figures on the waste factors reference; the pattern-repeat extra is a judgement based on how installers handle printed vinyl. The planks-per-box figure is rounded to the nearest whole plank because boxes hold whole planks. The guide to buying LVP explains the repeat trap and how to check a box before you open twenty, and the underlayment guide covers when a separate pad is allowed.
The assumptions behind the numbers
| Assumption | Default | Where it comes from |
|---|---|---|
| Plank | 7 × 48 in (18 × 122 cm) | The most common LVP size in US stores |
| Coverage per box | 23.6 sq ft (2.2 m²) | Typical 7 × 48 in LVP; MSI lists 23.77 sq ft per carton, other makers 18.9 to 26.1 (product pages, 2025) |
| Waste | 10 / 15 / 20% by layout | Industry rule of thumb, see the waste factors page |
| Pattern repeat | +5% | A judgement for printed products with few face images |
| Underlayment | none with a pad; 1 to 1.5 mm otherwise | Typical rigid-core LVP installation instructions |
Assumptions last reviewed October 8, 2026.
The calculator does not lay the planks out, so it does not show the last-row width or whether to rip the first row; the plank layout calculator does. It does not count transition strips, quarter round, the moisture barrier over a slab or the stair nosings, each of which has its own calculator. And it assumes one product in one dye lot; check the lot numbers on every box before you open them.
Two worked examples
An 18 × 14 ft kitchen-dining room
7 × 48 in planks with an attached pad, 23.6 sq ft boxes at $52, straight layout.
- Floor area: 18 × 14 = 252 sq ft; with 10%: 277 sq ft
- Boxes: 277 ÷ 23.6 = 11.75, rounded up to 12 boxes (283 sq ft), $624
- Planks: 10 per box, 120 in all; spare 31 sq ft
Twelve boxes, no underlayment, and a little over a box spare. That spare box is worth keeping in a kitchen, where a dropped knife or a dragged appliance is the usual reason to replace a plank.
520 sq ft on the diagonal, printed pattern, no pad
7 × 48 in planks in 18.91 sq ft boxes, diagonal layout, pattern repeat ticked, 100 sq ft underlayment rolls.
- Waste: 15% for the diagonal + 5% for the repeat = 20%
- Area to order: 520 × 1.20 = 624 sq ft
- Boxes: 624 ÷ 18.91 = 33.0, so 33 boxes; about 264 planks
- Underlayment: 520 × 1.05 ÷ 100 = 5.5, rounded up to 6 rolls
A small box, a diagonal layout and a printed pattern all push the order up; the same room straight, in 23.6 sq ft boxes and without the repeat, would need 25 boxes. That gap is the reason to read the label before comparing prices per box.
Where to find your inputs
Coverage per box and plank size. Both on the box end and the product page. Use the coverage exactly as printed.
Room or area. Wall to wall at floor level, including closets. For an odd shape, add the rectangles on the floor area calculator.
Pattern repeat. Open a box and count the distinct face images; if there are fewer than about eight, tick the box.
Attached pad. The box or product page says so. If in doubt, look at the back of a plank.
Common mistakes
- Assuming 20 sq ft a box. LVP boxes run from under 19 to over 30. Read the label.
- Foam underlayment under a padded plank. Two cushions break the click joints.
- Ignoring the repeat. Twelve identical planks in a row are obvious. Mix boxes and buy the 5%.
- No gap at the walls. Vinyl moves with heat. Leave 1/4 in and cover it with trim.
- Laying over a damp slab. Waterproof plank does not stop moisture under it from growing mould. Test the slab.
- Mixing dye lots. Check the lot number on every box before opening.
Questions people ask
- How many boxes of LVP do I need for 500 square feet?
- With 10% waste, 500 sq ft becomes 550 sq ft. At 23.6 sq ft per box that is 23.3 boxes, so 24; at 18.91 sq ft per box it is 29.1, so 30. The coverage on the box decides the answer, which is why the calculator asks for it.
- How much extra vinyl plank should I buy?
- 10% for a straight layout in a simple room, 15% for a diagonal or a room with many angles and doorways, 20% for herringbone. Add about 5% for a printed product with a short pattern repeat, so you can reject planks that would sit next to an identical one.
- How many planks are in a box of LVP?
- For 7 × 48 inch plank, usually 8 to 11; a 23.6 sq ft box holds 10 planks of 2.33 sq ft. Wider and longer planks come fewer to a box. The calculator works the count out from the plank size and the coverage, and warns if the two do not agree.
- Does LVP need underlayment?
- Most rigid-core LVP has a pad bonded to the back and needs no separate underlayment, only a 6 mil poly sheet over concrete if the maker asks. Planks without a pad take a thin underlayment of 1 to 1.5 mm approved by the maker; thick laminate foam is too soft and voids the warranty.
- Can vinyl plank go in a bathroom or basement?
- Yes, that is its main advantage over laminate. The plank itself is waterproof, though water can still get under it at the edges, so seal the perimeter in a bathroom with flexible caulk and deal with moisture coming up through a basement slab before laying it.
- What expansion gap does LVP need?
- Most makers ask for 1/4 inch at every wall and fixed object and a T-moulding past a run of about 50 feet. Rooms in strong sun or over radiant heat move the most. The expansion gap calculator has the figures by material.