Orpheus

How Much Flooring Do I Need?

Packs to buy, including the offcuts you will waste.

Inputs
m
m
m²

On the box. Laminate packs are commonly 1.8 to 2.5 m².

Diagonal and herringbone patterns waste considerably more at the edges.

Packs to buy
10
Floor area
20 m²
With 10% waste
22 m²
Coverage bought
22 m²
Spare after fitting
2 m² (10%)
Cost
240.00
Beading or skirting needed
18 m
packs = ⌈area × (1 + waste) ÷ coverage per pack⌉

Buy all packs in one order and check the batch number matches. Colour varies between production runs, and a plank from a different batch is visible under daylight — which is also why the spare 2 m² is worth keeping rather than returning.

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Multiply length by width, add a waste allowance of 10 to 25% depending on the pattern, then divide by the coverage per pack and round up. A 5 by 4 metre room at 10% needs 22 m² of coverage.

How to use Flooring Calculator

  1. Measure the room. Length and width in metres, at the widest points.
  2. Enter the pack coverage. Printed on the box, usually 1.8 to 2.5 m² for laminate.
  3. Choose the laying pattern. It sets the waste allowance, and the difference is large.

About calculating how much flooring is needed

Flooring quantities start as simple area arithmetic and are decided by the waste allowance, which varies far more than people expect. A straight lay in a rectangular room wastes around ten percent, almost all of it in the offcuts at the end of each row — and a good fitter starts the next row with the offcut from the last, which is what keeps the figure that low. A diagonal lay wastes twice as much because every board meets the wall at an angle, and herringbone more again. The allowance is set by the pattern rather than by the room. Two practicalities matter more than the arithmetic. The first is batch consistency: flooring is manufactured in runs and the colour drifts slightly between them, so a top-up order weeks later can arrive visibly different from what is already down. Buying the whole job at once from a single batch is the only reliable way to avoid it, and it is a stronger argument for generous ordering than the waste calculation is. The second is the expansion gap. Wood and laminate move with humidity, and a floor laid tight against the walls has nowhere to go — it lifts in the middle, usually in the first damp season, and cannot be corrected without taking it up. Ten to twelve millimetres around every edge, hidden by beading or skirting, is standard. Underlay is calculated separately on the plain area, since it comes off a roll with almost no waste.

Frequently asked questions

How much waste should I allow?
Ten percent for a straight lay in a simple rectangular room, fifteen for a room with alcoves or awkward corners, twenty for a diagonal lay and twenty-five for herringbone. The pattern matters more than the room size, because the waste is created at every edge cut.
Why does the batch number matter?
Colour and finish vary slightly between production runs, and the difference is invisible in a shop and obvious across a floor in daylight. Buying everything in one order from one batch avoids it, and it is the reason to over-order rather than top up later.
Should I keep the offcuts?
Keep at least a few full planks. A damaged board years later cannot be matched from a shop, since the product line will have changed or the batch will differ, and having spares turns a floor replacement into a twenty-minute repair.
Do I need underlay as well?
Almost always, unless the boards have it attached. It is calculated on the plain floor area with no waste allowance, since it is cut from a roll rather than laid in fixed lengths. A damp-proof membrane is a separate layer on concrete subfloors.
How much expansion gap should I leave?
Usually 10 to 12 mm around every edge, covered by beading or skirting. Wood and laminate expand with humidity, and a floor laid tight to the walls will buckle — this is the most common failure in a self-installed floor and it is not repairable without lifting it.

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