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Engineered Wood Flooring Calculator — Boards, Underlay & Transitions
Calculate engineered wood boards by width and length, 10% waste allowance, underlay rolls with tape, expansion gap and transition strips.
Longest dimension of the room
Shortest dimension of the room
Room not a simple rectangle? An L-shaped room is just two rectangles: measure each one wall to wall and add it as a section. Use three sections for a T or U shape. The calculator adds every section together.
10% standard, 15% for complex rooms
BS 8201: 10–15mm at all walls
UK packs vary ≈1.6–2.9m² — check the label
Standard: 15m² per roll
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How We Calculate This
This calculator determines board count from your room dimensions and chosen board size, then calculates underlay, tape and transition requirements.
For an L-shaped room, press Add section and enter each rectangle as its own section. Boards, packs and underlay are rounded up per section and then added together, so the estimate covers the extra cuts where the sections meet and never under-orders. Use three sections for a T or U shape.
The formula
Floor area with waste = Length × Width × (1 + Waste %)
Individual boards = Area with waste ÷ (Board width × Board length)
Packs = Area with waste ÷ Pack coverage (m²)
Underlay area = Floor area × 1.05 (5% allowance for overlap and trimming)
Underlay rolls = Underlay area ÷ Roll size (m²)
Flooring is sold by the pack, and pack coverage varies by brand (typically ≈1.6–2.9 m²), so packs are worked out from the area to cover rather than from the board count — adjust the pack coverage to match your product label. We also report the perimeter run that needs a 10–15mm expansion gap at all walls and obstructions (BS 8201:2011).
Frequently Asked Questions
Measure your room length × width and add 10% for wastage (cuts and fitting). For example, a 5m × 4m room is 20m², plus 10% = 22m² of flooring needed.
190mm is the most popular width for UK homes. Narrow 150mm planks suit smaller rooms and traditional styles. Wide 220mm+ planks create a modern, spacious feel but generate more waste in small rooms.
Yes, if floating (click-fit) installation. Underlay provides sound insulation, minor levelling and a moisture barrier. For stick-down installation on concrete, use a DPM instead. Pre-attached underlay boards don’t need separate underlay.
Leave a 10–15mm expansion gap around all walls, pipes and fixed objects. Engineered wood expands and contracts less than solid wood but still needs room to move. Cover gaps with skirting boards or beading.
Split the room into rectangles and enter each one as its own section using the Add section button; the calculator adds the sections together for you. Boards, packs and underlay rolls are rounded up per section before being added, which covers the extra cuts where board rows stop and restart at the junction between sections and never under-orders. Underlay tape is estimated per section from 1m wide strips, and the expansion gap run uses each section's full perimeter, a slight over-count at the join, so treat it as a safe upper figure. Use three sections for a T or U shaped room.
Pack coverage varies by manufacturer — UK engineered packs typically range from about 1.6m² to 2.9m² (common values include 1.81, 2.2 and 2.64m²), so there is no fixed board count. Always check the m² coverage printed on the product listing or pack label and enter it in the Pack coverage field for an accurate pack count. The default is 2.0m² per pack as a starting estimate.
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Last updated: June 2026
Verified against UK standards · estimates only, confirm with your supplier.