How much laminate flooring do you need?

How do I calculate how much laminate flooring I need?

Multiply the length of the room by its width to get square feet, add 10% for cuts, then divide by the square feet in one box and round up. A 12 by 15 ft room is 180 square feet; with 10% extra that is 198. At 20 square feet per box that is 9.9 — buy 10 boxes.

How much extra laminate should I buy?

About 10% for planks laid straight in a simple room, 15% for a diagonal layout or a room with many corners, closets and doorways, and 15 to 20% for herringbone. Keep an unopened box if you can: it makes repairs easy and most stores take back full boxes.

How many square feet are in a box of laminate?

Usually 15 to 25 square feet, depending on the plank size and thickness — thicker planks mean fewer per box. The exact figure is printed on the box and listed on the product page; enter it in Box covers. To compare two products, add the second box size under the table.

Do I need underlayment under laminate?

Yes, unless the planks come with a pad already attached. Underlayment usually comes in rolls of 100 square feet; the calculator counts the rolls for the same area as the flooring. Over concrete, use one with a vapor barrier, or lay a 6-mil plastic sheet first.

Should I include closets and the space under cabinets?

Include closets and any floor you will see. Leave out the space under kitchen cabinets and islands: laminate is a floating floor and should not be pinned down by heavy fixed cabinets. Measure each room or closet separately and add it with + Add another room.

Worked example: a room plus a closet

A living room of 14 by 18 ft is 252 square feet and a closet of 3 by 6 ft adds 18, for 270 square feet in all. Add 10% for a straight layout: 270 × 1.10 = 297.0 square feet. If the box on the label covers 22.6 square feet, that is 13.14 boxes, so round up to 14. The same floor laid on the diagonal needs 15% extra, 310.5 square feet, which is 14 boxes. You would have about 46.4 square feet left over from the straight layout, which is worth keeping for repairs. Underlayment for 270 square feet is 3 rolls of 100 square feet.

Why rounding up matters

Flooring is sold in whole boxes, and a box cannot be split. The allowance for cuts is a planning figure, not a guarantee: a room with many doorways, an angled wall or a pattern to match wastes more than a plain rectangle, and the last row is often ripped narrower, leaving an offcut that cannot be used elsewhere. Buying a box short means a second trip and a possible mismatch in color between production lots, so buy all boxes at once and compare the lot numbers on the cartons.

Measuring tips and mistakes

Measure each room at its longest and widest points and split an L-shaped room into rectangles, then add them. Do not subtract a doorway or a closet door opening: you will lay flooring through it. Do subtract a permanent island or full-height cabinets if you will not floor beneath them. Mixing feet and inches is the most common arithmetic error, since 14 ft 6 in is 14.5 ft, not 14.6. Enter the area per box from the label, not a guess from the plank size: a box of narrow planks and a box of wide planks of the same thickness can cover quite different areas.

Before you start laying

Most manufacturers ask you to let the unopened cartons sit flat in the room for about 48 hours so the planks match the room's temperature and humidity. A floating floor expands and contracts with the seasons, so it needs a gap at every wall and fixed object, covered later by baseboard or quarter-round. Typical instructions call for roughly 1/4 to 3/8 inch, and long runs or wide rooms (around 40 feet is a commonly quoted limit) get a transition strip where the floor must be allowed to move. Gap size and run limits differ between products, so the installation sheet packed with your flooring overrides any rule of thumb here. These items do not change the box count, but ignoring them is the usual reason a new floor buckles.

Sources: manufacturer installation guides for floating laminate floors (acclimation, perimeter expansion gap, transition strips for long runs), including those from Mohawk, Lawson and Pergo; waste allowances as described in the notes at the top of this page. Related tools: flooring calculator, square footage calculator, tile calculator and baseboard calculator.