A fence estimate starts with one number, the total length, and branches out from there. Walk the line with a measuring wheel or long tape and note every corner, end and gate.
Sections and posts
Subtract gate widths from the total, then divide by the post spacing (usually 1.83 m for 6 ft panels). Round up to get the number of sections. Posts = sections + 1, plus one extra for each gate (gates need a post on both sides).
Corners count too. If the fence turns a corner, the corner post is shared, so each separate straight run gets its own count.
Infill
For panel fences: one panel per section, plus gravel boards and clips or slotted concrete posts. For closeboard: feather edge boards overlapped by about 25%, on two or three arris rails per bay.
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 places.
Concrete
Post-mix (Postcrete-type) is the common choice. Budget about 2–3 bags of 20 kg per post, depending on hole size. The fence post concrete calculator works it out exactly from hole and post sizes.
Before you dig
- Confirm the boundary, and check planning limits: generally 2 m maximum, or 1 m next to a highway, without permission.
- Agree which side faces the neighbour. The "good side" usually faces out.
- Price waste removal for the soil you dig out.
This guide is general information for estimating. It is not engineering, legal or tax advice. Check the Building Regulations and Building Control for your project.