Plan laminate flooring and its underlay
A laminate floor plan needs more than box coverage. Check the subfloor, underlay or vapour layer, and the manufacturer’s expansion rules before placing an order.
Back to calculator ↑Measure the continuous floor
Measure internal width × length and deduct only areas that will remain unfloored, such as a stair opening. For an irregular room, divide the plan into rectangles and add their net areas. Record doorways and changes of room shape for the installer even if the arithmetic uses one total.
Decide plank direction and check actual plank dimensions before choosing waste. Door transitions and staggered joints affect cuts. Put any spare boards you want into the entered allowance; the engine does not add a second reserve.
Boxes and underlay have separate arithmetic
A 4 × 5 m room is 20 m². At 10% cutting allowance it needs 22 m² of laminate; with 2.2 m² per box, buy ten boxes. The underlay calculation runs only when you select the manufacturer-approved separate-underlay option.
If approved underlay covers 10 m² per roll and its separate allowance is 5%, it needs 20 × 1.05 = 21 m², so buy three rolls. That uses underlay’s own allowance, not the laminate’s 10% again. Confirm whether the chosen product has attached backing or specifies a particular layer.
Check moisture and movement details
Concrete may require a moisture test and a specified vapour control layer. The substrate must meet the product’s flatness and stability limits. Do not assume that every laminate can tolerate standing water because a surface finish is described as water resistant.
Floating laminate needs the specified expansion clearance at walls and sometimes transitions between rooms. Check underlay compatibility with the click joint and any acoustic or vapour requirements. Do not trap the floor under fixed fittings in a way its instructions prohibit.
Complete the shopping plan
Verify the exact SKU and labelled box coverage. A per-box price uses whole boxes, while a per-m² price uses purchased coverage; labour uses net floor area. Unknown prices are omitted from the subtotal rather than estimated.
Budget separately for skirting, transition profiles, vapour layer, subfloor work and delivery. Check that boxes come from a consistent batch and store any spare planks as the manufacturer directs. Bring the measurement plan to the installer for a layout check.
Common questions
Is all laminate waterproof?
No. Check the selected product’s moisture and wet-area limits, including joints and substrate.
Why are three underlay rolls needed in the example?
Underlay needs 21 m² after its 5% allowance; at 10 m² per roll that rounds to three.
Is a floor-only price the total installed cost?
No. The subtotal includes only entered prices; labour, layers, preparation and trims may still be missing.
Sources and calculation guidance
Check these against your chosen product’s label and instructions.