Fence Calculator

Calculate fence panels, posts, sections, and rails from total length, panel width, post spacing, and gates. Optional estimated panel cost.

ft
ft
ft
$
Fence panels / sections
15
Fence length (ft)120
Panels15
Posts17
Sections15
Rails (approx.)30
Gates1
Estimated panel cost$675.00
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How to use this fence calculator

A fence calculator is a materials takeoff: how many panels, how many posts, and how many rails. Post spacing is usually 6 or 8 ft on center; vinyl kits follow the panel width. Each gate typically needs its own extra post. This is not the installed-price tool — use the Fence Cost Calculator when you want a $/ft budget including labor.

Wood privacy fences often use three rails; ranch rail uses two or three. Corners already sit on the post-spacing math if you measure the actual run. Add a few extra pickets if you are building panels yourself instead of buying pre-made ones.

Formula

Panels / sections = ceil(length ÷ panel width). Posts ≈ floor(length ÷ post spacing) + 1 + gates (extra post at each gate). Rails ≈ sections × rails per section. Panel cost = panels × price.
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Worked example

120 ft of 8 ft panels, 8 ft post spacing, one gate, two rails: 15 panels, 17 posts, 30 rails. At $45/panel, panels alone are $675 (posts, concrete, and gates extra).

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Frequently asked questions

How many fence posts do I need?

Length ÷ spacing, plus one, plus extras at gates and sometimes corners if you measured as one long run around a corner.

How many fence panels for 100 feet?

At 8 ft panels, 13 panels (ceil(100/8)). Confirm the last bay is not a skinny leftover your kit cannot fill.

Does this include concrete for posts?

No. Plan roughly one 50 lb bag per hole in mild climates, more for frost-depth footings.

Wood vs vinyl panel width?

Both are often 6 or 8 ft. Enter the actual kit width.

Where is the cost estimate?

Optional price per panel. For wood/vinyl installed $/ft including gates, open the Fence Cost Calculator.

Results are estimates for informational purposes and are not financial, legal, or professional advice. Last reviewed 2026-08-19.