Fence Calculator
Enter the total fence length and your post spacing to get the number of posts, sections, rails and pickets for a wood picket or privacy fence.
Result
- Sections
- 13
- Rails
- 26
- Actual post spacing
- 7.69 ft
Counts are for one straight run. Add one post for each extra corner or end where runs do not share a post, and two posts for each gate.
Formula
- Sections = fence length ÷ post spacing, rounded up
- Posts = sections + 1
- Rails = sections × rails per section
- Pickets = fence length ÷ (picket width + gap), rounded up
How the Fence Calculator works
A fence run is a row of sections with a post at each end of every section. That is why a straight run needs one more post than it has sections.
Pickets are counted across the full length. Each picket takes up its own width plus one gap. A privacy fence uses a gap of zero or close to it.
Posts are usually set 6 to 8 feet apart. Closer spacing makes a stronger fence and suits windy sites.
Worked example
A 100 ft fence with posts every 8 ft has 100 ÷ 8 = 12.5, so 13 sections and 14 posts. With 2 rails per section that is 26 rails. Pickets 5.5 in wide with a 0.5 in gap take 6 in each, so 1,200 ÷ 6 = 200 pickets.
Frequently asked questions
How many fence posts do I need for 100 feet?
With 8 foot spacing you need 14 posts: 13 sections plus one end post. With 6 foot spacing you need 18 posts.
How deep should fence posts be set?
A common rule is one third of the post length in the ground, and below the frost line in cold climates. A 6 foot fence usually uses 8 foot posts set 2 feet deep.
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