A fence estimate starts with one number, the total length, and branches out from there. Walk the line with a measuring wheel or a long tape and note every corner, end, gate and change in ground level. Those features drive post counts and labour far more than the length itself.
Walking the line
Before measuring, confirm exactly where the fence goes. Mark both ends and every corner with stakes. Note obstacles (trees, sheds, drainage, existing walls) and how the ground slopes along the line. On slopes, decide with the client whether the fence will step down in level sections or follow the ground. Stepped panels need taller posts and plinth boards, or extra infill below.
Sections and posts
Subtract gate widths from the total, then divide by the post spacing (usually 2.4 m for Colorbond and paling fences). Round up to get the number of sections. Posts = sections + 1 for a straight run, plus one extra for each gate (gates need a post on both sides). Corners count too: each corner post is shared, so treat each straight run separately and add them up.
Infill
For Colorbond (steel) fences: one panel kit per bay, made up of infill sheets with a top and bottom rail, on steel posts at 2.4 m centres. For paling fences: palings = fence length ÷ paling width (about 7 per metre with 150 mm palings butted, more if lapped), on two or three 75 × 50 mm rails per bay, with a plinth board along the bottom.
Post length and depth
A rule of thumb is to bury a third of the post's total length, or half the height above ground. For a 1.8 m fence, that means 2.4 m posts with 600 mm in the ground at minimum. Use 2.7 m posts in exposed spots. Gate posts carry more load, so go bigger and deeper.
Concrete
Rapid-set concrete in 20 kg bags is the common choice. Budget about 2–3 bags per post, depending on hole size. The fence post concrete calculator works it out exactly from hole and post sizes. Gravel in the bottom of each hole helps drainage and post life.
Gates
Gates are priced as their own item: the gate, hinges, latch, drop bolt for double gates, and stronger posts. Check which way it opens, and allow for a slope across the opening, which can stop it swinging.
Removing the old fence
Old posts set in concrete are slow to remove. Price removal and disposal separately, and say in the quote whether new posts go in the same holes (often impossible with old concrete) or alongside.
Before you dig
- Confirm the boundary, and lodge a free Before You Dig Australia (BYDA) request to locate services. Check your state's dividing fence rules: neighbours usually share the cost of a standard dividing fence, and written notice is normally required first.
- Agree which side faces the neighbour. The "good side" usually faces out.
- Price waste removal for the soil you dig out.
- Check for roots and services near each hole.
A worked example
30 m of 1.8 m Colorbond fence with one 0.9 m gate: 29.1 m ÷ 2.4 m = 12.1, so 13 bays and 15 posts (14 + 1 extra for the gate). 13 panel kits (sheets and rails), and about 35 bags of 20 kg rapid-set concrete. Plus the gate kit, hinges and latch.
The fence calculator handles Colorbond and paling fences, and the chain link calculator counts every fitting for wire fences.
Common questions
Timber or steel posts?
Galvanised steel posts are standard for Colorbond fences and increasingly common for paling fences, because they don't rot and termites can't eat them. H4 treated pine or hardwood posts suit traditional paling fences and cost less up front.
How long does a fence take?
Setting posts is the slow part, especially with rock or roots. A crew can often set posts one day and hang infill the next, once the concrete has gone off.
Pricing checklist
- Total length measured, with corners, ends and gates marked
- Posts counted per run, plus extras for gates
- Infill, rails, plinth boards and caps listed
- Bagged concrete counted from real hole sizes
- Old fence removal and disposal priced or excluded
- Slopes, roots, rock and access noted
- Gate hardware listed
Labour on fencing is mostly digging and setting posts. On hard or rooty ground, a post auger or breaker hire can save more than it costs.
This guide is general information for estimating. It is not engineering, legal or tax advice. Check the NCC, Australian Standards and your building surveyor or certifier for your project.