Calculation details
Planning estimate only. Verify dimensions, waste, coverage, product specifications, and local requirements before purchasing materials.
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What does this calculator estimate?
A fence material calculator estimates posts, rails, and pickets for a straight fence run. Enter the fence length, section length, rails per section, and picket width to plan your materials.
- Posts = sections + 1
- Sections = ceil(length ÷ section length)
- Pickets = ceil(length × 12 ÷ picket width)
How fence materials are estimated
A fence is built in sections between posts. Dividing the total run by the section length gives the number of sections; each section needs rails, and the picket count comes from the picket width and spacing over the total length.
Limitations to watch for
The estimate is for a straight run with evenly spaced pickets. Gates, corners, slopes, and existing posts change the counts. Picket spacing (if any) must be added to the width. Concrete, hardware, and caps are not included.
How to use it in practice
Measure the fence run in feet. Pick a section length that matches standard post spacing (6–8 ft). Enter the actual picket width plus spacing. Add a gate and corner posts manually.
['Enter the total fence length.', 'Enter the section (post spacing) length.', 'Enter rails per section and picket width; the tool computes the counts.']
How this calculator works
Formula
Sections = ceil(fence length ÷ section length). Posts = sections + 1. Rails = sections × rails per section. Pickets = ceil(fence length × 12 ÷ picket width).
Worked example
A 120 ft fence with 8 ft sections: 15 sections, 16 posts. With 2 rails per section: 30 rails. With 5.5 in pickets: ceil(120 × 12 ÷ 5.5) = 262 pickets.
Assumptions to verify
- A straight fence run with no gates or corners.
- Pickets are installed edge-to-edge at the entered width.
- Posts are placed at each section boundary.
Frequently asked questions
How many posts do I need for a fence?
Divide the run by the section length and add one: a 120 ft fence with 8 ft sections needs 15 sections and 16 posts.
How many pickets do I need?
Multiply the fence length in inches and divide by the picket width (plus spacing if any). A 120 ft fence with 5.5 in pickets needs about 262.
How far apart should fence posts be?
Commonly 6–8 feet apart for wood fences. Longer spans weaken the fence and require beefier rails.
Do I need corner and gate posts?
Yes — corners, gates, and ends often need thicker or set-in-concrete posts. The tool counts standard line posts only.
How many rails per section?
Typically 2 for a 4 ft fence and 3 for a 6 ft fence. Enter the number your design uses.
Does this include concrete and hardware?
No — plan for post concrete, screws/nails, hinges, and latches separately.
What if my yard isn't straight?
Break the run into straight segments and calculate each separately, adding corner posts.
Cite this tool
BoringToolsKit. “Fence Material Calculator.” boringtoolskit.com/fence-material-calculator/ (reviewed 2026-08-25). Free to reference in articles, syllabi, and answer posts with a link.
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