How many packs of flooring do I need?
Laminate, LVT and engineered wood are sold in packs that cover a fixed area. The calculator works out your floor area, adds a cutting allowance and divides by the pack coverage:
For irregular rooms, split the floor into rectangles, add up the areas and use "Total area" mode.
Wastage allowance by room
| Room / layout | Allowance |
|---|---|
| Rectangular room, straight lay | 5–7% |
| Rooms with alcoves, hearths, doorways | 10% |
| Diagonal or herringbone | 15%+ |
Fitting tips
- Leave packs flat in the room for 48 hours before fitting so the boards acclimatise.
- Check the subfloor is flat to within about 3mm over 2m. Use self-levelling compound to fix dips.
- Lay boards parallel to the longest wall or the main light source, and stagger end joints by at least 300mm.
- Undercut door frames so boards slide underneath, and use door bars at thresholds.
Worked example: a 4m × 4m bedroom
The floor is 16m². With 10% for cuts you need 17.6m². At 2.22m² per pack that's 7.9, so buy 8 packs (17.76m²). Underlay in 15m² rolls covers 16m² plus overlaps with 2 rolls. The perimeter is 16m; less 0.8m for the doorway, that's 15.2m of scotia, or 7 lengths of 2.4m, plus 1 door bar. At the default prices that's roughly £320 in materials.
Buy all the packs at once and check they share the same batch or shade number. Boards from different batches can differ slightly in colour and in how tightly the joints click.
Laminate, LVT or engineered wood?
- Laminate is the cheapest and hard-wearing, but most types don't like standing water. Look for an AC3 rating or higher for living areas, and a water-resistant range for kitchens.
- LVT (luxury vinyl tile/plank) is waterproof, warmer underfoot and good for kitchens and bathrooms. Rigid-core click LVT hides small subfloor dips better than thin glue-down vinyl.
- Engineered wood has a real wood top layer that can often be sanded once or twice. It costs more and needs care with moisture and underfloor heating limits.
Whichever you choose, follow the maker's instructions for underlay, expansion gaps and underfloor heating. They override general advice, including ours.
Get the subfloor right
Most flooring problems start underneath. Click floors need a flat base, typically within 2–3mm over 2m. Fill dips with self-levelling compound, and screw down any loose, creaking floorboards first. On concrete, use an underlay with a damp-proof membrane. A new sand and cement screed must be fully dry before flooring goes down, which can take weeks: the screed calculator gives a rough drying time.
Common flooring mistakes
- No expansion gap. Boards butted tight to the walls buckle in summer. Keep 8–10mm all round, including at pipes and door frames.
- Short end joints lined up. Stagger joints by at least 300mm so they don't form a weak line across the floor.
- Too little wastage on awkward rooms. Bay windows, chimney breasts and several doorways eat boards. Use 10% unless the room really is a simple rectangle.
- Fitting kitchen units on top. Floating floors shouldn't be pinned down by heavy units. Fit the flooring up to the plinths instead.
To finish the room, the skirting board calculator works out new skirting. For tiled floors, use the tile calculator. More indoor calculators are in floors, walls and decorating.