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).
Assumptions and limitations
The estimate covers a straight run from the length and spacing you enter. Corners, gates, slopes and obstacles all add posts and change the layout, and it does not include concrete, fixings or gravel boards. Buy a little extra for cuts and the odd warped board, and confirm quantities against your final design.
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.
Who should use this tool
Homeowners and DIY builders planning a straight run of fence who want a materials list of posts, rails and pickets before ordering. Useful for garden boundaries and privacy fences, and for checking a contractor's material count against your own.
Benefits
- Estimates posts, sections, rails and pickets by length
- Helps you order a complete materials list
- Adds the extra end post to close the run
- Free and browser-based, handy for planning
Practical use cases
- Planning materials for a garden boundary fence
- Estimating pickets for a privacy fence
- Checking a contractor's material count against your own
- Budgeting a straight fence run before ordering
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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.
How does spacing affect the number of posts?
Wider spacing needs fewer posts but longer, heavier rails that can sag, while closer spacing costs more posts but gives a sturdier fence. The tool divides your run by the spacing you choose and adds one post to close the end, so try a couple of spacings to compare materials.
Does this include gates and corners?
No. The estimate is for a straight run, so add posts wherever the fence turns a corner or meets a gate, since these need their own support. It also excludes concrete, fixings and gravel boards, so add those separately based on your final layout.