Fence post calculator — how many posts do I need?
Turn your fence length and post spacing into a post count, then add posts for gates, free ends and corners.
Calculator
A 200 ft run at 8 ft on center is 25 sections → 26 line posts, plus 3 for gates, ends and corners = 29 posts. Spacing 6–8 ft o.c. is a labeled typical — heavier/taller fences use closer spacing.
Posts are the backbone of a fence and the first thing to count. Along a straight run, posts sit one spacing apart, and you always need one more post than the number of spans — the closing post at the far end. So the count is sections + 1, where sections is the line length divided by the spacing, rounded up.
Then the corners and gates add up. Every free end, every change of direction (a corner) and every gate opening needs its own post, over and above the straight-run count. An open run that starts and stops — one or two sides of a yard, with a gate — typically carries three or four of these extra posts. A fence that closes all the way back on itself is counted differently, below. Gate posts should also be heavier and set deeper than line posts — size those with the gate width & post calculator.
Spacing itself is a planning choice, not a fixed rule. 6–8 ft on center is typical for wood and vinyl; tall privacy fences, heavy panels and windy sites use closer spacing, while chain-link runs its line posts up to 10 ft apart. Tighten the spacing input and watch the post count climb.
Formula
sections = ceil(line_length_ft ÷ post_spacing_ft)\nline_posts = sections + 1\ntotal_posts = line_posts + extra_posts (gates + ends + corners)
The +1 is the closing post of a straight run. Each gate opening, free end and corner adds exactly one post to extra_posts.
A closed loop drops the +1. When the fence comes all the way back to where it started — an enclosed yard, paddock or garden — the last post is the first one, so posts = ceil(perimeter ÷ spacing), corners included. Enter the perimeter as the line length, leave extra posts at 0, and take one off the total this straight-run formula returns.
Worked example
200 ft run at 8 ft spacing, with one gate and two corners (3 extra posts):
- sections = ceil(200 ÷ 8) = 25
- line posts = 25 + 1 = 26
- total = 26 + 3 = 29 posts
Reference table
Line posts by run length (straight run, before gates and corners):
| Length | 6 ft | 7 ft | 8 ft | 10 ft |
|---|---|---|---|---|
| 50 ft | 10 | 9 | 8 | 6 |
| 100 ft | 18 | 16 | 14 | 11 |
| 150 ft | 26 | 23 | 20 | 16 |
| 200 ft | 35 | 30 | 26 | 21 |
| 300 ft | 51 | 44 | 39 | 31 |
| 500 ft | 85 | 73 | 64 | 51 |
Add one post for each gate, free end and corner.