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 8 ft for wood fences). 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 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.
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, that means 8 ft posts with 2 ft in the ground at minimum. Go deeper in frost zones and windy sites.
Concrete
Fast-setting concrete is the common choice. Budget about 1.5–2 bags of 50 lb per post for a 4×4 in a 10" hole. The fence post concrete calculator works it out exactly from hole and post sizes.
Before you dig
- Confirm property lines and HOA rules, and call 811 to locate utilities.
- 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 local codes and your inspector for your project.