How it works
Fence posts mark the ends of each section, so a straight run always has one more post than the number of gaps between them. Divide the total length by your post spacing, round up, then add one to get the total post count.
Panels are the sections between posts. If you know your panel width, the calculator can tell you how many fit along the fence. Leave the panel width blank if you're only interested in post count.
Worked example
Two examples below — one in US units, one in metric.
- Fence length is 100 ft, post spacing is 8 ft.
- Divide: 100 ÷ 8 = 12.5 sections.
- Round up: ceil(12.5) = 13 sections.
- Add one for the end post: 13 + 1 = 14 posts.
- If panel width is 8 ft: ceil(100 ÷ 8) = 13 panels.
Install 14 posts and 13 panels.
- Fence length is 30 m, post spacing is 2.4 m.
- Divide: 30 ÷ 2.4 = 12.5 sections.
- Round up: ceil(12.5) = 13 sections.
- Add one for the end post: 13 + 1 = 14 posts.
Install 14 posts.
Common questions
Why is it posts = length ÷ spacing, plus one?
Fence posts mark the ends of each section, so a straight run always has one more post than the number of gaps between them — a single 8 ft section needs 2 posts, not 1. That's the '+1'.
Should I round the post count up or down?
Always up. A fractional result means the last gap would be narrower than your spacing, not that you can skip a post — rounding down would leave a section unsupported.
Does this account for corners or gates?
No — it assumes one straight run. For an L-shaped or rectangular fence line, calculate each straight section separately and add the totals; corner posts are typically shared between two sections rather than double-counted.