The number of fence posts comes from one formula, plus a “+1” that trips people up: posts = (fence length ÷ post spacing) + 1. You add one because a straight run needs a post at both ends — five sections of fence take six posts.
Pick your spacing first
| Fence type | Typical post spacing |
|---|---|
| Wood privacy / picket | 6–8 ft |
| Chain-link | 8–10 ft |
| Vinyl panel | Panel width (6 or 8 ft) |
| Ranch / split-rail | 8–11 ft |
Closer spacing means a stiffer fence; wider spacing saves posts but flexes more. For most wood fences, 8 ft is the practical maximum.
Worked example
A 120 ft straight run at 8 ft spacing: 120 ÷ 8 = 15 sections, + 1 = 16 posts. If the run doesn’t divide evenly, round sections up so no span exceeds your spacing. A 100 ft run at 8 ft = 12.5 → round to 13 sections → 14 posts.
Don’t forget the extras
Add a post at every corner and at both sides of every gate. Gate posts often need to be larger or set deeper because they carry swinging weight. Count each straight run separately, then add corner and gate posts.
Frequently asked questions
Why do I add one post? A straight fence line always has one more post than sections, because both ends need a post.
How far apart should fence posts be? 6–8 ft for wood, up to 8–10 ft for chain-link.
Do corners count as extra posts? Yes — calculate each straight run on its own, then add posts for corners and gates.