How many fence posts do I need?
For a straight fence, the number of posts is the fence length divided by the post spacing, plus one. A 100 ft fence with posts every 8 ft needs 14 posts (13 sections + 1 end post) — before adding posts for corners and gates.
The formula
Sections = fence length ÷ post spacing, then posts = sections + 1
The "+1" is the end post that closes the last section. Then add one extra post at every corner and a sturdy pair of posts for each gate.
A worked example
- Fence length: 100 ft, posts every 8 ft
- Sections: 100 ÷ 8 = 12.5 → round up to 13 sections
- Posts: 13 + 1 = 14 posts for the straight run
- Add posts for corners and gates on top of that
Let the calculator count it
Enter your fence length and post spacing into our fence calculator to get posts, panels, and an estimated cost instantly.
Open the Fence CalculatorChoosing post spacing
| Fence type | Common spacing |
|---|---|
| Pre-made panels | 6 or 8 ft (match the panel) |
| Wood picket / privacy | 6–8 ft |
| Chain link | up to 10 ft |
Don't forget the concrete
Each post is usually set in concrete — about 1–2 bags per post, depending on post size and hole depth. Once you know your post count, size the concrete precisely with our concrete calculator.