How many fence posts do I need?
Divide the fence length by the post spacing, round up and add one post for the end. A 100 ft wood privacy fence with posts every 8 ft has 13 sections and needs 14 posts, 39 rails with 3 rails per section, and 219 pickets 5.5 in wide.
Worked example: a 100 ft privacy fence
- Sections: 100 ÷ 8 = 12.5, rounded up to 13 sections.
- Posts: 13 sections + 1 = 14 posts.
- Rails: 13 sections × 3 rails = 39 rails.
- Pickets: 100 ft × 12 = 1,200 in ÷ 5.5 in = 218.2, rounded up to 219 pickets.
Posts needed by fence length
Straight runs with a post at each end and 5.5 in pickets with no gap.
| Fence length | Posts at 8 ft | Posts at 6 ft | Pickets |
|---|---|---|---|
| 50 ft | 8 | 10 | 110 |
| 100 ft | 14 | 18 | 219 |
| 150 ft | 20 | 26 | 328 |
| 200 ft | 26 | 35 | 437 |
| 300 ft | 39 | 51 | 655 |
How the calculator works
Sections = fence length ÷ post spacing, rounded up
Posts = sections + 1
Rails = sections × rails per section
Pickets = fence length × 12 ÷ (picket width + gap), rounded up
Most residential wood fences set posts 6 to 8 ft apart, according to Decks.com. Spacing posts 8 ft apart lets standard 8 ft rails span one section, while closer spacing makes a stronger fence in windy areas.
The count covers one straight run. Add one post for each corner and an extra post for each gate, and run the calculator separately for each side of the yard.
Frequently asked questions
How far apart should fence posts be?
Wood fence posts are typically set 6 to 8 ft apart. Vinyl fences can often use 8 to 10 ft spacing, depending on the panel manufacturer.
How many pickets are in an 8 ft fence section?
With 5.5 in pickets and no gap, an 8 ft section takes 96 ÷ 5.5 = 17.5, so 18 pickets. Posts take up some of the width, so the real number can be one less.
How many posts do I need for a 100 ft fence?
With posts every 8 ft, a straight 100 ft fence needs 14 posts. With posts every 6 ft it needs 18 posts.
Do I need extra posts for gates and corners?
Yes. Each corner needs a post where the two runs meet, and each gate needs a post on both sides, which usually means one extra post per gate.
Sources
- Decks.com, How Far Apart Should Fence Posts Be?
- Inch Calculator, Fence Calculator