Fence Calculator
Calculate the number of fence posts, rails, pickets and bags of concrete you need for any fence length. Works for timber, Colorbond and pool fencing. Metric and imperial.
🔨 Fence Calculator
📐 How It Works
Fence posts are spaced at regular intervals along the fence line. The number of posts is the number of bays plus one end post. Rails run between posts — one per rail per bay. Pickets are spaced along the fence at regular intervals.
📋 Worked Example
50m fence, 2.4m post spacing, 2 rails, 100mm picket spacing, 2 concrete bags/post: Posts = 22. Rails = 21 bays × 2 = 42 rails (100.8 lm). Pickets = 500. Concrete = 44 bags.
❓ Frequently Asked Questions
As a general rule: post hole depth = 1/3 of total post length. For a 1.8m fence using 2.4m posts: hole depth = 600–800mm. In soft or sandy soil go deeper. In cyclone zones or for taller fences always check local requirements and engineer's specification.
Timber paling fences: 2.4m post spacing. Colorbond: 2.0–2.4m depending on panel width. Pool fencing: as per AS 1926 — maximum 900mm between posts for most panel types. Check your local council requirements and fencing specifications.
Light posts in firm soil: 1 × 20kg bag. Standard timber posts: 2 × 20kg bags. Heavy posts or soft soil: 3 × 20kg bags. Mix to a stiff consistency — not too wet. The concrete should be slightly domed above ground level to shed water away from the post.
Fence posts in-ground contact require H4 treated pine (or equivalent) for above-ground conditions and H5 for posts in the ground and high decay risk areas. Never use untreated pine in the ground — it will rot within 2–5 years.