How the calculator works
A wood fence is sections between posts: sections = length ÷ spacing (rounded up), posts = sections + 1 for a straight run. Each section carries 2 rails (4 ft fence) or 3 rails (6 ft privacy). Picket count divides the fence line's inches by picket width plus gap, with 5% waste for splits and culls.
Worked example: 120 ft of 6 ft privacy fence on 8 ft centers: 15 sections, 16 posts, 45 rails, and 120×12 ÷ 5.5 × 1.05 = 275 pickets, plus ~32 bags of concrete.
Corners, gates, and slopes
- Corners and ends each add a post beyond the straight-run count. An L-shaped yard needs one more than a straight line of the same length.
- Gates: frame each with its own two posts (often 6×6 for wide gates), set deeper than line posts.
- Slopes: racked fences follow the grade (spaced pickets handle this well); stepped fences hold level panels and step down, and stepped needs slightly longer posts on the downhill side.
Material choices
- Posts: pressure-treated 4×4 rated for ground contact, no exceptions. Cedar pickets on treated posts is the classic combination.
- Rails: 2×4 × 8 ft treated; crown them upward.
- Fasteners: hot-dip galvanized or exterior coated screws. Plain steel bleeds black streaks down cedar within one season.