Decking Boards3.6m Grey Composite Board (0.52m²)
Woodgrain composite board — no staining, no rot, 25-year look. Covers ≈0.52m² per board incl. 5mm gap.
£14.95
£28.64 / m²
Decking Calculator — How Much Decking Do I Need?
Enter your deck measurements in metres and get exact board quantities, costs and a ready-to-order material list.
01 — The Calculator
How much decking does your garden need?
Pace out your plot and enter the measurements — the value engine prices every way to fill it, hippo bags, dumpy bags or handy sacks.
Enter dimensions to calculate.
Area
0.0 m²
Boards needed
0 boards
Wastage
+10%
Coverage
0.0 m²
Best price
—
Enter your plot size below — we'll price the cheapest way to cover it.
The Catalogue
Your Materials Catalogue
Browse and customise your personal price list below. The default prices shown are indicative — useful as a starting point for budgeting, but your actual merchant prices will vary.
Why set your own prices?
When you update a product with your negotiated merchant price, every estimate and project board you create will automatically use your rate. Your quotes reflect what you actually pay, not a generic average — giving you more accurate margins and faster, more professional estimates.
How it works
- 1Click “Customise your own prices” and find the product below
- 2Enter your merchant price
- 3Save — stored on this device, and synced to your trade account when logged in
- 4Every project board and trade estimate now applies your saved price automatically
Your custom prices can be updated at any time as your supplier rates change. Logged-in trade users: your prices follow you across every device.
Custom prices flow into the calculator, project board and trade estimates automatically.
Extras5 products
Decking BoardsDecking Boards3.6m Teak Composite Board (0.52m²)
Warm teak-toned composite board with hidden-clip fixing. Covers ≈0.52m² per board incl. 5mm gap.
£15.50
£29.69 / m²
Decking Boards3.6m Softwood Board (0.48m²)
Classic grooved softwood deck board, pressure treated. Covers ≈0.48m² per board incl. 8mm gap.
£7.95
£16.60 / m²
Decking Boards2.4m Softwood Board (0.32m²)
Shorter grooved softwood board for small decks and staggered joints. Covers ≈0.32m² per board.
£5.50
£17.24 / m²
Decking Boards100-pc Fixings Pack
Stainless decking screws plus hidden starter clips and driver bit — one pack fixes roughly 20 boards.
£12.95
£12.95 each
Default prices are indicative only — confirm with your merchant before ordering.
Worked example — a 3.6m × 3m deck
- 1Deck measures 3.6m × 3m = 10.8m².
- 2Boards run the 3.6m way; at 150mm per row (145mm board + 5mm gap) the 3m width needs 20 rows — 20 boards.
- 3Add 10% for cuts and staggered joints: order 22 boards.
- 4At roughly 0.54m² coverage each, 22 boards cover the 10.8m² deck with offcuts to spare.
Decking coverage and laying guidance
- Joists at 400mm centres for timber boards; 300–350mm for most composite boards.
- Leave a 5–8mm gap between boards and 10mm where the deck meets walls.
- Softwood boards need a UV-protective oil every 1–2 years; composite just needs washing.
- Lay a weed membrane under low decks to stop growth pushing up between the boards.
Related calculators and guides
- Pergola and timber calculator — posts and rails for the frame
- Fencing calculator — screen the edges of your deck
- Weed membrane calculator — ground cover under low decks
- Full depth guide for every material
Reviewed by the Garden Calculator editorial team.
Common questions
With standard 145mm boards laid with a 5mm gap, each board covers 150mm of deck width — about 6.7 board-metres per square metre. A 3.6m board therefore covers roughly 0.54m² including its gap. Enter your deck area above and the calculator gives an exact board count with 10% added for cuts.