Flooring arrives in sealed packs, and the pack is the only unit a store will sell you. The room gives you an area, the carton gives you a coverage figure, and the gap between those two numbers is where most orders go wrong. A bedroom measuring 5 meters by 4 meters holds 20 square meters of finished surface, but a pack that covers 2.2 square meters turns that area into a division with a forced round up at the end. This page does that division with the waste allowance already inside it, so the number you carry to the counter is a pack count rather than an area.
What the coverage figure on a pack really buys
Every carton prints a coverage figure, and that figure describes finished installed surface rather than the loose board area inside the box. A pack rated at 2.2 square meters is the same quantity as 23.68 square feet, 2.63 square yards, or 3,410 square inches, because the National Institute of Standards and Technology fixes the square foot at exactly 0.09290304 square meters, which makes the square yard 0.83612736 square meters. North American cartons are normally labeled in square feet and European packs in square meters, so a plan drawn in meters read against a label printed in feet will be wrong by a factor of about 10.76 until somebody converts. Enter the coverage in the same system as the room measurements, every time. Batch identity matters as much as the arithmetic. Planks are printed and pressed in production runs, and two lots of the same product code can differ slightly in tone, so buy the whole floor in one purchase instead of returning for a single pack three weeks later.
Measuring a room that is not a perfect rectangle
- Sketch the floor as rectangles. Draw the room on paper and cut it into simple rectangles before you pick up the tape. Give every rectangle a letter, and leave space beside each one to write its two dimensions in meters or feet as you take them. Tool: Pencil and paper.
- Measure at the baseboard line. Run the tape along the floor at the baseboard rather than at hand height, because walls lean and plaster thickens near the ceiling. Hook the tape into the corner and read the number where the opposite baseboard meets the floor. Tool: 25 foot tape measure.
- Take each pair of walls twice. Rooms are rarely square, so measure both long walls and both short walls. Use the larger figure of each pair in the calculator, and note the difference, because a room out of square by more than 20 millimeters needs a tapered first row. Tool: 25 foot tape measure.
- Add closets, bays and thresholds. Measure every closet floor, bay recess, and door threshold as its own rectangle, then add those areas to the main figure. A closet of 0.9 meters by 0.6 meters adds 0.54 square meters, which is roughly a quarter of a 2.2 square meter pack.
- Copy the coverage off the carton. Read the coverage figure from the printed product label rather than from the shelf ticket, and check whether it is stated in square meters or square feet. Enter that exact number in the coverage field without rounding it first. Tool: Product carton.
- Set the waste percent from your plan. Choose the waste field from the pattern you actually intend to lay, not from the pattern in the showroom photograph. A straight run down the long wall and a herringbone field in the same room are not the same order at all.
Waste follows the layout, not a habit
The waste percentage is a prediction about offcuts, not a superstition. Pergo's installation guidance says to add 5 percent for a standard room and 10 percent when the room has many corners or angles. Those two allowances can land on the same whole-pack result: in a 20 square meter room with 2.2 square meter packs, both 5 percent and 10 percent round up to 10 packs. Room shape drives the choice harder than room size does. A corridor 1.2 meters wide takes a lengthwise rip on every row, and a herringbone field turns each board into two angled cuts. Closets, door openings, and hearth cutouts each leave an offcut that is rarely long enough to open the next row. Use the manufacturer's 5 or 10 percent guidance as the starting point, then ask the product supplier or installer for a layout-specific takeoff when the pattern falls outside that published scope.
| Layout type | Extra material in source | Multiplier applied | Packs at 2.2 m2 per pack |
|---|---|---|---|
| Standard room | 5% | 1.05 | 10 packs |
| Room with many corners or angles | 10% | 1.10 | 10 packs |
Source: Pergo, How much flooring is required for my space?.
The two percentages are Pergo manufacturer guidance. The final column independently applies the calculator formula to a 20 m2 room with 2.2 m2 packs and rounds only at the end.
A 5 by 4 meter bedroom laid in straight planks
| Field | Value |
|---|---|
| length | 5 |
| width | 4 |
| coverage | 2.2 |
| waste | 10 |
The room runs 5 meters along the window wall and 4 meters across, which is 20 square meters, or 215.28 square feet. The packs on the shelf are labeled 2.2 square meters each. Because the plan includes a closet opening and several angled cuts, this example uses the 10 percent figure Pergo publishes for rooms with many corners or angles. The tool multiplies 20 by 1.10 to reach 22 square meters of material, divides that by 2.2, and lands on exactly 10.0, so the round up changes nothing and the order is 10 packs. A standard rectangular room at Pergo's 5 percent figure also rounds to 10 packs here. Raise the allowance beyond 10 percent only when the exact product supplier or installer documents why the layout needs it. Length and width move raw material need directly, while carton coverage moves it inversely. In this example, reducing coverage about 9.1 percent from 2.2 to 2.0 square meters raises the raw need 10 percent from 10 to 11 packs. Whole-pack rounding can hide or expose smaller changes, so the largest real uncertainty depends on room measurement, layout, and the exact carton label.
Result: 10 packs.
Common mistakes
- Entering a carton coverage printed in square feet while the room itself was measured in meters.
- The division does not check units, so a coverage of 23.68 entered against an area of 20 square meters returns a single pack and looks briefly plausible. Convert the label first, using the exact factor of 0.09290304 square meters per square foot, then enter the area and the coverage in one system.
- Adding the waste allowance by hand and then leaving the waste field at 10 percent as well.
- The allowance lands twice, so a 20 square meter room is ordered as though it covered 24.2 square meters and the count climbs by a full pack. Type the raw measured area into the length and width fields and let the waste percent do that work once, then compare the output with your hand figure.
- Ordering the shortfall a few weeks later and receiving planks from a different production run.
- Color and gloss are set per run, so a late pack can read as a patch under daylight even when the product code on the carton matches exactly. Buy the whole floor plus one spare pack in a single purchase, and keep the batch number from the carton with your project notes.
- Measuring only the widest point of a room that is visibly out of square.
- The narrow end still needs full width boards, and the surplus cut from the wide end is not usable elsewhere once it has been tapered. Measure both pairs of walls, order from the larger pair, and plan a scribed first row wherever the difference exceeds 20 millimeters.
- Assuming the underlayment is packed inside the flooring cartons.
- Foam and felt underlayment is sold separately in rolls with its own coverage figure, so a correct pack count still leaves the floor without a base layer. Run the same area figure against the roll coverage printed on the underlayment label, and buy both items in the same trip.
Moisture decides whether the order survives the winter
A pack count assumes the boards stay the size they were on delivery day, and wood based flooring moves with the air around it. The Building America Solution Center sets the target equilibrium moisture content for new wood flooring at 6 to 9 percent, and asks for room conditions near 70 degrees Fahrenheit, which is 21 degrees Celsius, at 30 to 50 percent relative humidity before installation starts. Kiln dried lumber leaves the kiln at 6 to 8 percent, and rot has been reported once wood passes 20 percent moisture content. Those thresholds change the order in a practical way. If the delivery has to sit in the room for several days to settle, the packs need floor space outside the work area, and if a few boards cup or crown during that wait you will want spare material instead of a second trip. Keep at least one unopened pack from the same run as repair stock.
Where a plank order stops and a trade starts
Some conditions are not solved by adding packs. A subfloor that dips more than the flooring maker allows will telegraph through a floating floor and open the locking joints, and leveling compound is priced by bag and by area rather than by pack. A concrete slab that has never been tested for moisture is a genuine risk under vinyl and engineered boards, and slab testing is an instrument job rather than a tape measure job. Stairs, thresholds against tile, radiant heating loops, and joists that flex underfoot all belong to an installer. Regional conditions matter as well. A house on the Gulf coast and a house in the dry southwest do not hold the same indoor humidity, so the same product settles at different points inside the 6 to 9 percent band. Settle the substrate question before the material is ordered, because a delayed floor stored in a damp garage is a wasted order.
Frequently asked questions
How many packs do I need for 200 square feet?
Convert the area first, then divide. A 200 square foot floor is 18.580608 square meters, using the exact factor of 0.09290304 square meters per square foot. With a 10 percent waste allowance that becomes 20.44 square meters of material to buy. Divided by a 2.2 square meter pack it gives 9.29, and because the store sells whole packs the answer is 10 packs. The same floor with no allowance at all divides into 8.45 packs, which the store still fills as 9 packs.
Should the waste allowance go on before or after dividing by pack coverage?
Before the division, always. The formula multiplies length by width, applies the allowance to that area, and only then divides by the coverage per pack, so the extra material is bought inside the same packs as the rest of the floor. Applying the allowance afterwards inflates a pack count that has already been rounded up, which counts the rounding twice. The difference is most visible in small rooms, where one pack can be a tenth of the whole job.
Why does one extra point of waste add a whole pack?
The result is rounded up to whole packs, so the answer only moves when the division crosses an integer. In the worked example above, 20 square meters at 10 percent divides into exactly 10.0 packs. Raise the allowance to 11 percent and the same room needs 10.09 packs, which a seller fills as 11. Nothing about the floor changed, only the side of a boundary the arithmetic happened to land on.
How much spare flooring should I keep once the job is done?
Keep at least one full unopened pack from the same production run, stored flat and indoors rather than in a garage or attic. Repairs are the reason. A damaged board in the middle of a floor is replaced by opening the field around it, and a pack bought two years later will not match the run you laid. That spare pack is also cover against a leaking appliance in a kitchen or a laundry.
Does the perimeter expansion gap change how much flooring I buy?
Not in a way the area arithmetic can see. The gap hides under the baseboard or trim, so the boards still span the full room width and the last row is ripped narrower rather than left out. What the gap does change is the offcut pattern, because a 10 millimeter allowance, which is 0.394 inches, narrows the field by 20 millimeters across the room and usually leaves the last row as a ripped sliver. Measure wall to wall and let the waste percent absorb the rips.
Related calculators
Sources
- How much flooring is required for my space? Pergo. Manufacturer guidance to add 5 percent for a standard room and 10 percent for a room with many corners or angles; those are the only sourced allowances presented in the table. Accessed 2026-09-06.
- NIST Guide to the SI, Appendix B9: Factors for Units Listed by Kind of Quantity National Institute of Standards and Technology. Gives the exact conversion factors quoted on this page, 9.290304 E-02 square meters per square foot, 8.361274 E-01 per square yard and 6.4516 E-04 per square inch, which turn a carton label into the unit used in the calculator. Accessed 2026-09-06.
- Wood Moisture Content Building America Solution Center, Pacific Northwest National Laboratory. Source of the acclimation figures used here, an equilibrium moisture content of 6 to 9 percent for new wood flooring, room conditions near 70 degrees Fahrenheit at 30 to 50 percent relative humidity, and the 20 percent rot threshold. Accessed 2026-09-06.
This is a planning result, not a supplier quote; sellers use different pack, bag, board, roll, and bundle conventions, so confirm the exact product label and selling unit before you order.