Flooring Plank & Pack Calculator

How the flooring calculation works

We start with the net floor area: length × width. For an L-shaped room, split it into rectangles, calculate each and add them together.

Next we add a wastage allowance: total area = net area × (1 + waste %). Planks are counted by dividing the total area by one plank's face area (length mm ÷ 1000 × width mm ÷ 1000), and packs by dividing by the pack coverage. Both are always rounded up — you can't buy part of a box.

Cost is based on the full packs you'll actually buy: packs × pack coverage × price per m².

Why staggered joints create wastage

Click-lock planks must have their end joints staggered — typically at least 300–500mm between joints on neighbouring rows — so the floor is structurally locked and doesn't show a repeating "ladder" pattern. That means the first and last plank in each row is cut to length. Some off-cuts can start the next row, but offcuts shorter than the minimum stagger or recommended minimum plank length (often 300mm) can't be used and become waste.

Around doorways, radiator pipes, hearths and out-of-square walls you'll lose more. A straight, simple room with a 5% allowance is tight; 10% is the sensible default for a staggered lay; herringbone and chevron patterns have angled cuts at every perimeter so allow 15% or more.

Top tips

Buy all packs from the same batch to avoid colour variation, acclimatise boards for 48 hours in the room, and keep one spare pack for future repairs.

Typical UK flooring plank sizes