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 kickboards, or extra infill below.
Sections and posts
Subtract gate widths from the total, then divide by the post spacing (usually 8 ft for wood 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 picket or privacy fences: pickets = fence length ÷ (picket width + gap). For board-on-board, boards overlap by about a quarter of their width, so you need roughly a third more. Rails are 2 or 3 per section depending on height: 6 ft fences usually take three.
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 6 ft fence in Canada, that usually means 10 ft posts with about 4 ft in the ground, below the frost, so frost heave doesn't lift them. Gate posts carry more load, so go bigger and deeper.
Concrete
Fast-setting concrete in 30 kg bags is the common choice. Budget about 3–4 bags per post for a 4×4 in a 10" hole 4 ft deep. 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 property line and your municipality’s fence bylaw (back-yard fences are often limited to about 2 m, or 6 ft 6 in), and request a free locate through Click Before You Dig.
- 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
100 ft of 6 ft privacy fence with one 4 ft gate: 96 ft ÷ 8 ft = 12 sections, so 14 posts (13 + 1 extra for the gate). Rails: 3 per section = 36. Pickets at 5½" with no gap: about 210, plus 5% = 220. Concrete: about 42 bags of 30 kg fast-setting mix for posts 4 ft deep. Plus nails or screws, a gate kit and post caps.
The fence calculator handles picket and board-on-board fences, and the chain link calculator counts every fitting for wire fences.
Common questions
Wood or concrete posts?
Pressure-treated wood posts rated for ground contact are standard. Steel posts in the ground with wood framing are a longer-lasting option.
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 set.
Pricing checklist
- Total length measured, with corners, ends and gates marked
- Posts counted per run, plus extras for gates
- Infill, rails, kickboards and caps listed
- Concrete or post-mix 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 local codes and your inspector for your project.