Fence Calculator
Calculate fence posts, sections, and even post spacing for straight runs without gates. Estimate panels, rails, pickets, gate allowances, and waste for other layouts.
Enter measurements below. The result updates as you type.
Calculation breakdown
Usable run
96 ft total - 4 ft gates
Sections
Usable fence is split into independent runs at gates, then rounded conservatively because exact gate positions are not entered.
Posts
Straight run uses endpoints plus line and gate posts.
Waste
Panels, rails, and pickets include 10% planning waste where applicable.
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Fence post spacing calculator examples
How many posts and how far apart?
For one straight fence run without gates, divide the fence length by your maximum allowed spacing, round sections up, then add an endpoint post. Divide the length by the rounded section count to space posts evenly without exceeding your chosen maximum.
| Straight run | Max spacing | Sections | Posts | Even spacing |
|---|---|---|---|---|
| 40 ft | 8 ft | 5 | 6 | 8 ft |
| 75 ft | 8 ft | 10 | 11 | 7.5 ft |
| 100 ft | 8 ft | 13 | 14 | 7.69 ft |
Eight feet is an illustrative maximum, not a universal code requirement. Gates, corners, slopes, panel lengths, soil and local regulations can change the layout. The live result gives even spacing only for one ungated straight run; verify other runs separately.
More Fencing help
Related calculators and guides
Open the project hub for nearby tools, measurement guidance, and published articles.
Formula explanation
Core fence estimate basis
Usable length = total fence length - gates; sections = usable length / post spacing
- The calculator rounds section and material counts up; a straight ungated run also shows equal spacing after section rounding.
- Gate openings should be deducted or treated separately from straight runs.
- Post-count logic must account for ends and layout transitions.
Worked example
Straight run example
96 ft fence run with 8 ft section spacing
- 1Divide the run length by the planned section spacing.
- 2Round sections up when needed.
- 3Add posts based on the final layout rules.
Base sections: 12, before gate or terminal post adjustments.
Estimate assumptions
Check these assumptions before ordering
- Corner, end, gate, and terminal posts need explicit handling.
- Panel and picket formulas differ and are calculated by fence style.
- Terrain, layout breaks, and local code may change post depth or spacing.
Measurement checklist
How to measure
- For straight runs, measure the total fence path from end to end.
- For a closed rectangular perimeter, measure the outside length and width.
- Measure gate openings separately and enter the number of gates plus width per gate.
- Use the planned post spacing, panel width, picket width, and picket gap from your product or layout.
Avoid these errors
Common mistakes
- Counting gate openings as usable fence length.
- Using panel formulas for individual picket fences.
- Forgetting extra gate posts or corner posts on perimeter layouts.
- Assuming post spacing can exceed local code, product, or site requirements.
Estimate disclaimer
Verify before ordering.
Use the output as a planning baseline. Site conditions, product coverage, waste, supplier units, installation method, and local requirements can change the final quantity.
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Published guides
Understand the measurements and assumptions
Supporting guide
How Many Fence Posts Do I Need?
Calculate fence posts from usable fence length, chosen spacing, layout type, endpoints, corners, gates, and material style.
Read guide
Supporting guide
How Much Concrete Do I Need per Fence Post?
Estimate concrete for fence-post holes with a cylinder formula, bag-yield checks, and links to the fence and concrete calculators.
Read guide
Supporting guide
Fence Cost per Foot: Length, Posts, Gates, and Material Scope
Compare fence cost per foot with the measurement and material assumptions that make wood, vinyl, chain-link, and gate quotes different.
Read guide
Common questions
Use the result with context
01Can this fence calculator estimate both panels and pickets?+
Yes. Wood/privacy mode estimates panels, while picket mode estimates individual pickets from picket width plus gap.
02How far apart should fence posts be?+
Enter the maximum planned spacing from your fence system and local requirements. On a straight run without gates, the calculator rounds up the number of sections and shows the resulting equal post spacing. For example, a 100-foot run with an 8-foot maximum needs 13 sections and 14 posts, spaced about 7.69 feet apart.
03How many posts do I need for a straight fence?+
For one straight run without gates, divide fence length by the maximum post spacing, round the section count up, then add one endpoint post. A 40-foot fence at an 8-foot maximum uses 5 sections and 6 posts. Gates, corners, and independent runs change the count.
04How should gates be handled?+
Gate openings are deducted from usable fence length, and two gate posts are added per gate.
05Can this replace a code check?+
No. Fence height, setbacks, post depth, and permit rules may depend on local requirements.