Decking Project Estimator
Calculate decking boards, joists, posts, screws and ground preparation materials for a complete deck build.
Results - Decking Project Estimator
How this decking estimator works
This estimator builds a practical bill of materials for a ground-level deck using common 2026 UK assumptions: decking laid over joists at 400mm centres, 150mm noggins, two structural bolts per post, plus weed membrane and sub-base for ground preparation. Pick a board length of 2.4m, 3.6m or 4.8m and choose a wastage allowance of 5%, 10% or 15% depending on how simple or complex your layout is.
Popular sizes
These decking presets cover the board-and-joist sizes people actually price up for garden platforms, seating areas and raised decks.
Garden decking searches usually revolve around standard entertainment areas, hot tub surrounds and raised seating platforms. Pages such as 2.4m × 1.8m, 3m × 1.8m, 2.4m × 2.4m, 3.6m × 1.8m create direct landing pages for board counts, joists, posts, screws and ground preparation materials.