Laminate Flooring Calculator

Laminate Flooring Calculator

Plan a laminate floor from the plank size on the pack. Enter your room, the plank length and width and the number of planks per pack, and get the packs to buy, the underlay rolls and the length of beading or trim for the edges.

Packs from plank sizeUnderlay & trimMetric & imperialLast updated: November 3, 2026

Calculate laminate

m
m
mm
mm
planks
%
m²

Laminate flooring formula

Coverage per pack

Pack = plank length × plank width × planks per pack

1,285 × 192 mm × 8 planks = 1.974 m². Most packs also print this figure.

Packs

Packs = ⌈room area × (1 + waste%) ÷ pack coverage⌉

Underlay and trim

Underlay rolls = ⌈area × 1.05 ÷ roll coverage⌉  ·  Trim = perimeter × 1.1

Underlay sheets butt together or overlap slightly, so allow about 5%. Beading or scotia covers the expansion gap around the edge; 10% extra covers mitres.

Worked example: 5 m × 4 m room

  1. Pack = 1.285 × 0.192 × 8 = 1.974 m²
  2. Area 20 m² + 10% = 22 m² → 22 ÷ 1.974 = 11.1 → 12 packs
  3. Underlay = 20 × 1.05 ÷ 15 = 1.4 → 2 rolls
  4. Trim = 18 m × 1.1 = 19.8 m (e.g. 9 × 2.4 m lengths)

Choosing underlay and trims

UnderlayBest for
Foam with damp-proof membraneConcrete subfloors (always use a DPM on concrete)
FibreboardUneven timber floors, better sound insulation
Acoustic rubber or high-density foamUpstairs rooms and flats
Thin foil-facedOver underfloor heating (low thermal resistance)

Skip extra underlay if your laminate has a pre-attached pad; doubling up can make the joints flex and fail.

Fitting essentials

  • Leave an expansion gap of 8–10 mm (about ⅜ in) at every wall, pipe and doorway.
  • Stagger the end joints by at least 300 mm (12 in) from row to row.
  • Acclimatise the packs flat in the room for 48 hours.
  • Lay along the longest wall or towards the main light source for the best look.

Frequently asked questions

How many packs of laminate do I need for 20 m²?

With 1.97 m² packs and 10% waste, 22 m² ÷ 1.97 = 11.2, so 12 packs.

How much extra laminate should I buy?

10% for a straight lay in a normal room, 15% for diagonal, and keep one spare pack for repairs.

Do I need underlay for laminate?

Yes, unless the boards have underlay pre-attached. It smooths minor bumps, reduces noise and, with a DPM, protects against moisture from concrete.

Flooring CalculatorAny floor by box Vinyl Flooring CalculatorSheet or LVT Skirting Board CalculatorSkirting lengths

Results are estimates. Follow the manufacturer’s fitting instructions and expansion gap requirements.

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