Calculators · Laminate Flooring Calculator

Laminate floors

Laminate Flooring Calculator

Add your rooms to get the boxes, planks and underlayment rolls of laminate, plus the rows and the expansion gap.

Area 1

Shape

Length

Width

Waste, from the Pergo guide

Pick one to fill the box next to it, or keep Custom.

Waste to add (%)

Empty counts as 0%.

Square feet per box

Optional. Read it on the box. Empty skips the boxes.

Planks per box

Optional. Needs the square feet per box too.

Underlayment roll (sq ft)

Optional. The coverage printed on the roll.

Room width across the rows

Optional. The side the planks run away from, like 10 or 10'6".

Plank width (in)

Optional. The width you see on the floor, like 7.5.

Expansion gap, from the Pergo guides

Pick one to fill the box next to it, or keep Custom.

Expansion gap (in)

Per wall, like 1/4 or 0.375. Used for the rows.

How to work out how much laminate you need

Laminate is sold in boxes of planks, so the job is to turn a floor area into whole boxes. You can read each step in the result above.

Area. Multiply length by width in feet for each room and add them. A 12 ft by 10 ft room is 120 square feet.
Waste. Pergo says to add 10% for standard installations and 15% for diagonal ones. With 10% you multiply by 1.10, so 120 becomes 132 square feet.
Boxes. Divide by the square feet in one box. With 20 square feet per box, 132 ÷ 20 = 6.6.
Round up. You need 7 boxes. That is 140 square feet, so 20 square feet are left over.
Planks. If you know the planks per box, the calculator also counts planks. A 20 square foot box with 8 planks means 2.5 square feet each, so 132 ÷ 2.5 is 52.8, or 53 planks.

What the Pergo guides say

The numbers here come from the Pergo installation guides, the ones we could open and read in full (checked October 2026). The three copies we found do not say the same thing, and that is useful to know before you buy.

Item	What the guide says
Waste	Add 10% to your square footage for standard installations. For diagonal installations, add 15%. Both copies of the installation guide say it (undated copy and rev. 01/2014).
Expansion gap	1/4 inch in the undated copy. 3/8 inch in the rev. 01/2014 copy and in the Pergo MAX instructions. It goes around the room and any fixed object such as pipes or columns.
Long runs	Areas over 66 feet in length or width need a 1/2 inch gap and a T-molding in the undated copy. The rev. 01/2014 copy says 40 feet.
Subfloor	Flat to within 3/16 inch over 10 feet. The guides say to fill low spots and sand high ones.
Acclimation	Unopened cartons lie flat in the room for 48 to 96 hours, depending on the climate (undated copy).
Moisture barrier	Over concrete, a 6 mil polyethylene film with the seams overlapping 8 inches, unless you follow an equivalent barrier’s directions.
Plank layout	Pergo MAX says the first piece must be at least 8 inches long and the end joints of neighboring rows must be offset by at least 12 inches.

The gap changed between copies, so the calculator lets you pick either one or type your own. Your box and its guide have the last word.

Example: a 12 ft by 10 ft room

Step	Calculation
Area	12 × 10 = 120 sq ft
With 10% waste	120 × 1.10 = 132 sq ft
Boxes of 20 sq ft	132 ÷ 20 = 6.6, rounded up to 7 boxes
Planks, 8 per box	132 ÷ 2.5 = 52.8, so 53 planks, and 56 come in the 7 boxes
Underlayment, 100 sq ft rolls	120 ÷ 100 = 1.2, rounded up to 2 rolls
Perimeter for trim	2 × (12 + 10) = 44 ft, before doorways

Rows and the last row

Laminate runs in rows, and the last row is cut to whatever is left. The calculator takes the room width across the rows, removes the gap on both walls, and divides by the plank width. Take the same 10 ft wide room with 7.5 inch planks:

Gap per wall	Space for planks	Full rows	Last row
1/4 in	119.5 in	15	7.00 in
3/8 in	119.25 in	15	6.75 in

Both give 16 rows in all. None of the Pergo guides we opened says how narrow a last row may be. The Pergo MAX instructions only say to trace the wall contour on a full width plank and cut it. If the last row comes out as a thin strip, ask Pergo or your installer what your product allows before you start.

Underlayment and trim

Some laminate has a foam pad attached and some does not. Pergo says the planks go over a foam underlayment when the product does not have one attached, and over concrete they also need a vapor barrier. How far a roll goes is printed on its label, so type that number and the calculator turns the floor area into rolls. It uses the floor area with no waste added, so check the label for how much the seams overlap. The perimeter line adds up the four sides of every rectangle you entered. It does not take off doorways and it counts a shared wall twice, so treat it as a rough start for quarter round or baseboard.

Other floors and tools

For a whole house with different floors, use the flooring calculator. For a floor that uses solid or engineered boards, there is the hardwood flooring calculator, and for waterproof planks the vinyl plank flooring calculator. If you only need a room’s area, the square footage calculator does that.

What this tool does not cover

Layout. It counts from the area. It does not plan where the cuts fall or the stagger of the end joints.
Other brands. The waste and the gap come from Pergo guides. Other makers can ask for something different.
Price. No prices are shown, because they change by store and region. Take your numbers to your supplier and ask for a quote.

Frequently asked questions

How do I work out how much laminate flooring I need?

Multiply the length by the width of each room in feet and add the rooms. Add your waste, divide by the square feet on the box and round up. Pergo says to add 10% for a standard install and 15% for a diagonal one. For a 12 ft by 10 ft room, 120 × 1.10 = 132 square feet. With 20 square feet in a box, that is 6.6 boxes, so 7 boxes.

How much laminate flooring do I need for a 12x12 room?

A 12 by 12 foot room is 144 square feet. With 10% waste you need 158.4 square feet. If a box covers 20 square feet, that is 7.92 boxes, so 8 boxes. With a diagonal layout and 15% waste it is 165.6 square feet, so 9 boxes. Enter the box size from your own carton to get your number.

How many planks do I need, not only boxes?

Fill in the square feet per box and the planks per box. The calculator divides the square feet per box by the planks per box to get the area of one plank, then divides your total with waste by that. In the 12 ft by 10 ft example with 8 planks in a 20 square foot box, 132 square feet needs 53 planks. The 7 boxes hold 56.

How big a gap should I leave around laminate flooring?

It depends on the product. One copy of the Pergo guide asks for 1/4 inch around the perimeter and fixed objects. Another copy, marked rev. 01/2014, asks for 3/8 inch, and so does the Pergo MAX guide. Read the guide that comes with your box and type that gap into the calculator.

Do I need underlayment for laminate flooring?

Pergo says that, depending on the product, the room and the subfloor, you may need a sound underlayment or a 6 mil polyethylene film as a moisture barrier. Over concrete it asks for the film, with the seams overlapping 8 inches. Planks with an attached foam may not need a separate underlayment. Check your product, then type the square feet on the roll label to count rolls.

How much extra laminate should I buy for a diagonal layout?

Pergo asks for 15% on a diagonal layout, against 10% for a standard one. That is five points more. On a 144 square foot room it is 144 × 1.15 = 165.6 square feet, against 158.4 at 10%. Pick the 15% option in the waste list or type your own.

How long should laminate acclimate before I install it?

The Pergo guide we opened asks you to lay the unopened cartons flat in the room for 48 to 96 hours before you start, depending on the climate. In a very dry or very humid climate it asks for at least 96 hours. Your own product may differ, so read its guide.