Flooring Calculator

Calculate how many packs of laminate, wood, or vinyl flooring you need. Enter room dimensions and pack coverage to get exact quantities with waste.

Area & Materials Calculator

Calculate floor, wall, and sloped surface areas from dimensions

Enter plan-view dimensions, slope applied

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Flooring calculation tips

Waste allowance for flooring

Straight lay: 5-10% waste. Diagonal: 10-15%. In rooms with lots of doorways, alcoves, or irregular shapes: 12-15%. Always buy full packs — you can't buy individual planks.

Acclimatising flooring

Laminate and engineered wood must acclimatise in the room for 48 hours before installation. Leave boxes flat, unopened, in the centre of the room. Do not install cold flooring in a warm room — it will expand and buckle.

Underlay types

Standard foam underlay: 3mm, for sound reduction only. Wood fibre underlay: 5-7mm, for sound and thermal insulation. Combination underlay with DPM: for concrete subfloors. Always use the manufacturer's recommended underlay.

Doorway transitions

Leave a 10mm expansion gap at all doorways and edges. Use T-profiles for same-height transitions, reducer profiles for different heights. Measure doorway widths before ordering transition strips.

Formulas used

Room area

A = length × width

With waste

A_total = A × (1 + waste%)

Packs needed

packs = ceil(A_total / pack_coverage)

Cost

cost = packs × price_per_pack

Worked example: 5m × 4m living room, laminate at 1.48 m²/pack, £28/pack

  1. 1Room area = 5 × 4 = 20 m²
  2. 2With 10% waste: 20 × 1.10 = 22 m²
  3. 3Packs needed: ceil(22 / 1.48) = 15 packs
  4. 4Underlay (15 m² rolls): ceil(22 / 15) = 2 rolls
  5. 5Cost: 15 × £28 = £420.00 (flooring only)
  6. 6Add underlay at £30/roll: +£60 = £480 total

Assumptions & limitations

When to ask a professional

For solid wood flooring (not engineered), installation over underfloor heating requires specialist advice. For concrete subfloors with high moisture content, a damp-proof membrane is essential. Uneven subfloors (deviation >3mm over 2m) need self-levelling compound before installation.

Frequently asked questions

How much laminate do I need for a 4m × 3m room?

Area = 12 m². With 10% waste: 13.2 m². If each pack covers 1.48 m²: ceil(13.2 / 1.48) = 9 packs. Check the pack — coverage varies by manufacturer and plank thickness.

How much underlay do I need?

Order the same area as your flooring plus 5% waste. Underlay comes in rolls (typically 10 m² or 15 m²) or as click-together tiles. For 12 m²: order 15 m² of underlay.

Can I install laminate over existing floorboards?

Yes, if the floorboards are flat and secure. Use combination underlay with DPM over concrete. Over wooden subfloors, lay at 90° to the existing floorboards for stability. Check for squeaks and fix before installation.

How much expansion gap do I need for laminate?

10mm minimum around all edges, doorways, and fixed obstacles (pipes, radiators). The gap is hidden by skirting boards or scotia/quarter-round beading. Failure to leave gaps causes buckling.