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Fence Calculator

Estimate the posts, rails or pre-made panels, pickets, gate posts, and concrete needed to build a fence — for privacy, picket, post-and-rail, or panel styles, in feet or meters.

Input

Feet in imperial, meters in metric — includes any gate openings.

Feet in imperial, meters in metric.

Center-to-center distance between line posts. Defaults to 8 ft / 2.4 m if left blank.

Horizontal rails between each pair of posts (e.g. top / mid / bottom).

Always in inches, regardless of the unit system above — boards are conventionally sized that way.

0 for a solid privacy fence; picket-style fences typically use a 1–2 in gap.

Feet in imperial, meters in metric. Defaults to 4 ft / 1.2 m if left blank. Ignored if gates is 0.

Output

Materials
MetricValue
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More ways to use this tool

REST API

curl -X POST https://api.iotools.cloud/v1/tool/fence-calculator \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "style": "privacy",
    "unitSystem": "imperial",
    "length": "100",
    "height": "6",
    "postSpacing": "8",
    "railCount": "3",
    "picketWidth": "5.5",
    "picketGap": "0",
    "numGates": "1",
    "gateWidth": "4"
  }'

Swap in your own key from your account. The tool's fields are the body — no wrapper.

Ask an AI agent

Use the IOTools `fence-calculator` tool (Fence Calculator) on this input:

YOUR_INPUT_HERE

Paste this at any agent connected to the IOTools MCP server, then add your input.

Embed widget

<iframe
  src="https://iotools.cloud/embed/fence-calculator/"
  width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
  title="Fence Calculator — iotools.cloud"
  sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
  allow="clipboard-write"
  style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>

Drop this into your own page — free, no key required, just a link back.

Cost per API/MCP callFrom 5 credits

Also available with

Guides

The Fence Calculator turns a total fence length, height, and post spacing into a shopping list: how many posts (line and gate), rails or pre-made panels, pickets, and bags of concrete to buy — for privacy, picket, post-and-rail, or panel fence styles.

How to use it

  1. Pick a fence style — privacy (solid boards), picket (spaced boards), post-and-rail, or panel (pre-made sections).
  2. Choose imperial (ft) or metric (m), then enter the total fence length and height.
  3. Set the post spacing (or panel width, for panel fences) if you don't want the default. Adjust rails per section, picket width/gap, and any gates as needed.

The materials table and a one-line summary update instantly.

The math

  • Effective fence length = total length − (gate width × number of gates) — line posts only span the parts of the fence that aren't a gate opening
  • Sections = ⌈effective length ÷ post spacing (or panel width)⌉, so line posts = sections + 1
  • Gate posts = 2 per gate — each gate gets its own dedicated pair of posts, not shared with the line-post run
  • Rails = sections × rails per section (privacy/picket/post-and-rail only — pre-made panels already include their own rails)
  • Pickets = ⌈effective length ÷ (picket width + gap)⌉ (privacy/picket only)
  • Post embedment depth = height ÷ 3 — bury about a third of the post, a widely cited framing rule of thumb
  • Concrete per post = the volume of a cylindrical hole (diameter = 3× the post's width, another common rule of thumb) at that embedment depth, minus the post's own volume, converted to bags using an 80 lb bag's ~0.6 ft³ published yield (the same figure the Concrete Volume & Bags Calculator uses)

Posts are assumed to be a standard nominal 4×4 (actual 3.5 in / 8.9 cm) regardless of unit system — this is a shopping-list estimator for planning purposes, not a structural design tool, so treat the concrete and picket counts as a starting point and round up for waste.

For example, a 100 ft privacy fence, 6 ft tall, with one 4 ft gate and 8 ft post spacing needs about 15 posts (13 line + 2 gate), 36 rails (3 per section), 210 pickets, and 30 bags of concrete.

Why exclude the gate from post spacing?

A gate needs its own two posts sized to carry the gate's hardware and swing — they aren't part of the regular line-post run. Subtracting the gate width before dividing by post spacing keeps the line-post count accurate to how a real fence gets laid out.

Does it account for corners or multiple runs?

No — this models one continuous straight run (the total length you enter), the same simplification most quick fence estimators use. For an L-shaped or multi-run yard, calculate each straight run separately and add the results together (each shared corner post only needs to be counted once).

For paint/coverage or concrete slab math elsewhere in a build, see the Paint Coverage Calculator and Concrete Volume & Bags Calculator.

Everything runs in your browser; no inputs are sent to a server.

fencefencingprivacy fencepicket fencepost and railgate postsfence postsconcrete for postsconstructiondiyyard

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