A multi-room flooring calculator that tells you exactly how many packs of laminate, hardwood or vinyl to buy, how much you will have left over, and what the whole job will cost. It is built for real projects where you are flooring more than one room at once and want a single, accurate order rather than guessing pack by pack at the checkout.
How it works
Start by choosing your units — metric (metres and square metres) or imperial (feet and square feet). Switching units converts your existing room measurements automatically, so you never lose your figures. Then add each room with its length and width; the tool multiplies them for the room area and sums every room into a single total floor area.
Next, tell it the coverage of one pack. You can type the coverage printed on the pack directly, or switch to plank mode and enter the plank length, plank width and the number of planks per pack — the calculator derives the pack coverage from those dimensions. Plank sizes are entered in millimetres because that is how manufacturers print them, and the result is shown back in your chosen area unit.
Finally, apply a waste allowance. Offcuts, breakages, doorway cuts and the staggered end-joints in a brick-bond lay all mean you buy more floor than the bare room area. Presets cover the common cases — 7 percent for a simple straight lay, 10 percent standard, 15 percent diagonal and 20 percent herringbone — or you can type your own. The tool grosses the area up by the waste percentage, divides by the pack coverage and rounds up to whole packs, because you cannot buy a fraction of a pack. Add a price per pack and optional underlay to get the material cost and all-in total, along with your exact leftover so you know how much spare stock you are keeping for repairs.
Formula note
The core calculation is: packs = ceil( (totalArea x (1 + waste%/100)) / packCoverage ).
Internally every area is normalised to square metres for accuracy — square feet are
converted with 1 ft squared = 0.09290304 m squared and plank areas with
1 m squared = 1,000,000 mm squared — then converted back to your chosen unit for
display. Underlay is sized to the bare floor area plus a small 5 percent overlap, then
rounded up to whole rolls.
Worked example
You are laying laminate across a 5 m by 4 m living room and a 3 m by 3 m hall.
That is 20 plus 9 equals 29 square metres of floor. With a 10 percent standard
waste allowance the order area becomes 31.9 square metres. At a common pack coverage
of 2.22 square metres, that is 31.9 / 2.22 = 14.4, which rounds up to 15 packs.
Those 15 packs actually cover 33.3 square metres, so you finish with about 4.3 square
metres of leftover — roughly two spare packs to keep for future repairs.
At 24 per pack the laminate costs 360. Add two underlay rolls at 18 each covering 10 square metres apiece, and the project total is about 396, or roughly 13.65 per square metre all-in. Every figure updates live as you adjust rooms, coverage, waste or prices, and nothing you type ever leaves your browser.