How Many Fence Posts Do I Need? Chart by Fence Length
Divide the fence length by the panel width or post spacing, round up, and add one: a 100 ft run with 8 ft sections needs 13 sections and 14 posts. Each extra straight run adds a post, and so does each gate.
Fence post chart
| Fence length | Posts, 6 ft spacing | Posts, 8 ft spacing | Concrete bags, 8 ft |
|---|---|---|---|
| 50 ft | 10 | 8 | 14 |
| 100 ft | 18 | 14 | 24 |
| 150 ft | 26 | 20 | 34 |
| 200 ft | 35 | 26 | 44 |
| 300 ft | 51 | 39 | 66 |
Concrete assumes 4×4 posts in 10 in holes, 30 in deep, with 6 in of gravel and 10% extra.
| Fence length | UK 1.83 m (6 ft) panels | AU 2.4 m panels |
|---|---|---|
| 10 m | 7 | 6 |
| 20 m | 12 | 10 |
| 30 m | 18 | 14 |
| 50 m | 29 | 22 |
Worked example: a garden with a gate
An L-shaped fence of 120 ft in two straight runs, with 8 ft sections and one 4 ft gate:
- Fenced length: 120 − 4 = 116 ft, split over two runs of 58 ft.
- Each run: 58 ÷ 8 = 7.25, so 8 sections. Both runs: 16 sections.
- Posts: 16 sections + 2 runs + 1 gate = 19 posts.
- Concrete: 33 bags of 80 lb mix.
Why the post count is one more than the sections
Every section sits between two posts, and neighbouring sections share a post. So a straight run always has one more post than sections. Where the fence turns a corner it starts a new run, so a corner post is shared and you add one post per extra run. A gate needs its own post on the latch side.
How deep should fence posts go?
Quikrete's guidance is a hole about three times the post's width and a depth of one-third to one-half of the post's height above ground, plus about 6 in of gravel in the bottom. Frost depth and local rules can require deeper holes. Our post hole concrete calculator works out the concrete for any hole size.
Common mistakes
- Spacing posts by panel width without the post. Measure post spacing centre to centre; panels and posts together set it.
- Forgetting the gate posts. Gates usually need heavier posts set deeper.
- Measuring along a slope. Measure the fence line along the ground; stepped panels on a slope may need extra.
