BCTheBuildingCode

How many fence panels do I need?

Enter your fence length and pick a panel width — you'll get the number of fence panels and posts to order, instantly. Switch to picket mode for a full material list: posts, rails and pickets. For example, a 30 m fence in 1.8 m panels needs 17 panels and 18 posts.

Fence panels to buy
17
+ 18 posts (30 m ÷ 1.8 m panel)

17 panels of 1.8 m panel cover your 30 m fence run, with 18 posts (one at each end plus one between every adjacent pair of panels). Order an extra panel or two if the run has tight corners or an awkward end.

Panels = fence length ÷ panel width, rounded up. Posts = panels + 1. Gates need additional hardware and usually wider gate posts — allow for them separately.

Common questions

How many fence panels do I need?
Divide your fence length by the panel width and round up. For example, a 30 m fence using 1.8 m wide panels needs ⌈30 ÷ 1.8⌉ = 17 panels. The fence calculator above does this instantly — just enter the length and pick the panel size.
How many fence posts do I need?
Posts = panels + 1. Every fence needs a post at each end, plus one between every adjacent pair of panels. So a 17-panel fence needs 18 posts. For a picket fence, posts = ceil(fence length ÷ post spacing) + 1 — use the picket mode in the calculator.
How many pickets do I need for a fence?
Divide the fence length by (picket width + gap) and round up. A 30 m fence using 3.5 in (90 mm) pickets with a 1.5 in (40 mm) gap allots 130 mm per picket, so 30,000 mm ÷ 130 mm ≈ 231 pickets. Add 5–10% for waste. Switch to picket mode in the calculator above.
How many rails do I need for a fence?
Rails per bay × number of bays. Bays = posts − 1. A fence with 18 posts has 17 bays; at 3 rails per bay that is 51 rails. Standard wood fences use 2–3 rails; taller or heavier fences often use 3. The picket mode in the calculator shows the rail count once you set the rails-per-bay figure.
How much fence do I need for my yard?
Measure all four sides of the area you want to fence — typically two lengths plus two widths for a rectangular yard. Add them up to get the total linear m of fencing, then enter that number in the calculator. Allow extra at corners, and measure twice — running short of panels after the posts are in is an expensive problem.
Does this calculator include post concrete or footing depth?
No — it counts panels, pickets, posts and rails only. Post depth and the amount of concrete depend on your soil type, post size, frost depth (for cold climates) and fence height. A 6 ft wood privacy fence in a cold climate typically sets posts at 3 ft deep, but confirm the depth and footing size with your fencing contractor or local building authority.

Want the full walk-through? Read the fence panel guide → Laying a new garden? Try the sod calculator →

Reference & education only. Not professional, engineering, or code-compliance advice. Estimates are based on published model codes; local amendments and your Authority Having Jurisdiction (AHJ) govern. Always verify against the current adopted code and a licensed professional before doing work.

Last reviewed 2026-07.

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