Fence Materials Calculator — m, posts, boards, cost
How to use this calculator
Enter total fence length and height in metres, centimetres, or millimetres, choose a fence type (privacy, picket, horizontal, or post & rail), then set post spacing, post and rail size, and board dimensions. The take-off drives your timber order — posts, rails, pickets, and 25 kg concrete bags rounded up per hole so you can read it off at the merchant.
Fence types — Privacy uses vertical boards with no gaps, Picket adds a gap between boards, Horizontal runs boards flat between posts, and Post & Rail has no infill boards.
Concrete — auto-calculates 25 kg bags needed per post hole based on post size and depth.
Hardware — optional nails/screws, post caps, and gate hardware.
Saved Calculations
| Time | Length | Height | Posts | Rails | Boards | Concrete | Total |
|---|
How to Calculate Fence Materials (Metric)
Sections = ceil(fence length ÷ post spacing); posts = sections + 1 (line posts plus one end post). Post spacing of 1.8–2.4 m suits residential timber fences under Eurocode 5 (EN 1995-1-1) good practice; 90×90 mm posts cover 1.2–1.8 m heights and 140×140 mm posts suit 2.4 m or gate posts. Rails are cut to the post spacing, so rail length feeds the same linear-metre tally as posts and boards. To price the timber list by volume, cross-check with the timber volume calculator.
Concrete for Post Holes
Each post hole is modelled as a cylinder: hole diameter = post width + 100 mm for 90×90 or + 150 mm for 140×140, depth as selected (60, 75, or 90 cm). Hole volume V = π·(d/2)²·depth is converted to 25 kg bags of concrete mix at ≈ 12 litres yield per bag. Typical result is 2–3 bags per 90 mm post and 4–6 per 140 mm. Set posts about ⅓ of their length below grade and below the local frost line.
Board and Picket Count
Privacy: boards = (length in mm) ÷ board width. Picket: pickets = (length in mm) ÷ (picket width + gap). Horizontal: boards per section = (height in mm) ÷ board width, times the number of sections. Post & rail has no infill. A 10–15% waste allowance covers off-cuts and culls — the same convention used in the metric deck calculator and stud wall calculator. For matching balustrade or top-rail runs, see the railing calculator.
On install day
Three numbers fence crews get wrong. Frost depth — Eurocode and most national codes require footings below the local frost line; UK/IE typical 75 cm, central Europe 80–100 cm, Nordics 120–180 cm. The 60 cm default in this calc is for mild climates only. Gate posts — upsize the two posts flanking any gate to 140×140 mm even on a 90×90 mm run, otherwise the gate will sag within a season. Concrete reality — installed timber fence in 2025 EU runs €40–90/m for 1.8 m privacy and €25–55/m for picket; material alone (this calc) is typically 35–45% of that. Order one extra 25 kg bag per 10 posts to cover dropped batches and oversized holes.
FAQ
Working in feet? Use the imperial fence calculator for the same logic in ft and inches. Do gate openings change the count? Gate posts are included in the post total; gate hardware is added under the Hardware section. Why round bags up per post? Each hole is its own pour — you can't share a half-bag between two posts on opposite ends of the run, so rounding per hole matches how the job actually goes.
