Laminate Flooring Calculator
Boxes from the room and the carton's coverage, rows and the last-row width, with the waste the lay pattern costs and the expansion gap the count must leave.
Boxes of laminate from the room and the coverage printed on the carton, with the waste the lay pattern actually costs and the expansion gap the count has to leave.
Quick answer: laminate boxes with 10 % waste
| Room | 18.7 ft² box | 20.0 ft² box | 24.1 ft² box |
|---|---|---|---|
| 100 ft² | 6 | 6 | 5 |
| 150 ft² | 9 | 9 | 7 |
| 200 ft² | 12 | 11 | 10 |
| 300 ft² | 18 | 17 | 14 |
| 500 ft² | 30 | 28 | 23 |
The three coverages American boxes carry. Use the one printed on yours; 5 % is enough for a clean rectangle, 15 % for closets, angles or a diagonal lay.
| Floor area | — |
|---|---|
| With waste | — |
| Boxes | — |
| Rows of planks | — |
| Last row width | — |
The number that matters is on the carton, not on this page. Laminate is sold by the box, and a box covers what its label says — 18.7, 20.0, 24.1 square feet, it varies by plank size and count. This page takes that figure as an input because any default would be a guess about a product you have not chosen yet. Read the carton, type the coverage, and the box count is arithmetic.
Waste is the lay, not the room. Every row ends in a cut, and the offcut starts the next row only if it is long enough to keep the end joints staggered. In a plain rectangle laid straight that costs about a tenth; a diagonal lay or a room full of closets and returns costs more, because the offcuts are triangles nobody can reuse. The three allowances above are the usual figures for those three cases, and they are allowances, not specifications.
The last row is where the plan shows. Divide the width by the plank width and the remainder is the strip along the far wall. A sliver under a third of a plank looks wrong and snaps badly; the fix is to rip the first row narrower so the two edge rows share the cut. The page prints the last-row width so that decision is made before the first plank goes down, not after the last.
Leave the gap. A floating floor moves with humidity and needs an expansion gap at every wall, typically ¼ to ⅔ inch, per the manufacturer’s instructions. It does not change the box count much; it changes whether the floor buckles in August.
The gap and the run limit are in the guide, and three American guides print the same ones. Pergo MAX, STAINMASTER waterproof laminate and Quick-Step Studio each ask for a concealed expansion space of at least 3/8 in. at the walls, with the flooring slid at least 1/4 in. under undercut door frames and wallbase. Each requires T-moldings in doorways 4 ft (1.22 m) wide or less and in rooms 40 ft (12.2 m) or more in length or width. HARO's Top Connect laminate, a German product, asks for 10 to 15 mm and an expansion joint in areas over 10 m (33 ft).
Acclimation is a condition, not only a wait. The same three guides give 48 hours with the unopened cartons in the room at 60 to 85 °F and 35 to 65% relative humidity. Those are the conditions the 48 hours are counted in, so the heating or the air conditioning has to be running while the cartons sit.
The run limit changes the order list, not the box count. A room 42 ft long is past the 40 ft line, so it is laid as two floating floors with a T-molding between them, and every doorway 4 ft or narrower takes its own molding. The boxes on this page do not change; the moldings are a separate line, sold by the piece, that this page does not count.
What I check on a job
Which way the rows run decides the last row. Before I trust this count I settle which way the planks run, because the page counts rows across whatever I type as the width. Swap length and width and the box count stays the same, but the rows and the last-row strip come out completely different, and the strip is the number I am actually checking. I measure that width at both ends of the room, since walls are rarely parallel and the sliver along the far wall follows the narrower reading. I also remember that the floor never reaches the wall: with the expansion gap left at both sides, the laid width is a little less than the room, which shifts the remainder the page prints. Then I read the left-over figure in the Boxes row. That is the only spare beyond the lay, because the waste percentage is already in the order and normal row-end offcuts use it up. If the left-over is close to nothing, one miscut row means another trip for one more carton.
Boxes = ceil(area × (1 + waste) ÷ coverage per box). Rows = ceil(room width ÷ plank width); the last row is the remainder of that division. Coverage per box is the carton’s figure. Waste allowances and the expansion gap are common practice and the manufacturer’s instructions respectively, not standards.
Worked example
A 15 × 12 ft room in laminate sold at 20 ft² a box: how many boxes?
- Area = 180 ft²; with 10% for a straight lay, 198 ft².
- 198 ÷ 20 = 9.9, so 10 boxes — 200 ft² bought, 2 ft² over.
- 7½ in planks across 12 ft: 144 ÷ 7.5 = 19.2, so 20 rows, and the last row is a 1½ in sliver.
10 boxes. The last row would be a sliver, so rip the first row narrower and let the two walls share the cut — the page flags it. Coverage per box comes off the carton, and that is the only number that decides the count.
8 values on this page were driven in a browser and compared with independently derived figures on 2026-10-29 (2808 values across 228 calculators site-wide).
Questions
How many boxes of laminate for 180 square feet?
10 boxes at 20 ft² a box with 10% waste (198 ft²). The coverage per box is on the carton and varies by product.
How much waste for laminate?
About 10% for a straight lay in an ordinary room, 5% for a clean rectangle, 15% for a diagonal lay or a room with closets and angles.
How wide should the expansion gap be?
Whatever the manufacturer's instructions say, typically ¼ to ⅔ inch at every wall, because a floating floor moves with humidity. It barely changes the box count; it decides whether the floor buckles in August.
What do I do if the last row is a sliver?
Rip the first row narrower so the two edge rows share the cut. A last row under a third of a plank looks wrong and snaps badly. The page prints the last-row width, the remainder of room width ÷ plank width, so the decision comes before the first plank goes down.