Flooring Calculator: Square Footage, Planks and Packs
Flooring is sold by area, so the job is to measure the room accurately, add a waste allowance for cuts, and convert the total into whole packs. Laminate, engineered wood, vinyl and solid timber all follow the same arithmetic — only the waste percentage changes.
Measuring correctly
Measure at the widest points, including doorway recesses and alcoves, and break L-shaped rooms into rectangles. Rooms are rarely square, so measure width at both ends and use the larger figure. Include the area under radiators and freestanding furniture, but you may exclude fitted kitchen units and built-in wardrobes.
Waste allowances
- Rectangular room, straight lay: 5-7%.
- Irregular or multi-angled rooms: 10%.
- Diagonal or herringbone patterns: 15%.
- Long planks in a small room: increase the allowance — offcuts are less reusable.
Underlay, expansion and acclimatisation
Most floating floors need an underlay of the same area, plus a damp-proof membrane on concrete subfloors. Leave a 10-12 mm expansion gap at every wall, covered by skirting or beading. Let the packs acclimatise in the room for 48 hours before fitting so the boards settle to the room's humidity and do not lift later.
Key takeaways — Flooring Calculator
- Order area = measured area × (1 + waste allowance), rounded up to whole packs.
- Add underlay and any damp-proof membrane to the material list.
- Acclimatise the flooring and leave an expansion gap at every edge.