Estimate posts, rails and pickets for a fence by length.
Calculated instantly in your browser.
How do you calculate fence materials by length?
Sections = length ÷ spacing (rounded up); Posts = sections + 1; Rails = sections × rails per section; Pickets = length (in) ÷ (picket width + gap). The extra post closes the run. For example, a 100 ft fence with 8 ft spacing needs 13 sections, 14 posts, 39 rails and about 209 pickets. Add posts for gates and corners.
Understanding your result
One extra post closes the run. Add posts for gates and corners, and buy a little extra material to allow for cuts and the odd warped board.
Formula and method
Sections = length ÷ spacing (rounded up). Posts = sections + 1. Rails = sections × rails per section. Pickets = length (in) ÷ (picket width + gap).
Worked example
A 100 ft fence with 8 ft spacing needs 13 sections, 14 posts and 39 rails — about 209 pickets at 5.5 in with a 0.25 in gap.
How to use this tool
- Enter the total fence length in feet.
- Set the post spacing and rails per section.
- Optionally add picket width and gap, then press Calculate.
About the Fence Calculator
The Fence Calculator estimates how many posts, sections, rails and pickets you need for a straight run of fence.
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Frequently asked questions
How far apart should fence posts be?
Six to eight feet is typical for wood fences. Closer spacing is stronger; the calculator lets you set whatever spacing you plan to use.