Planning a fence
A 100 ft fence at 8 ft spacing needs about 13 sections and 14 posts.
Fence Calculator
Fence - figures update as you type, nothing leaves your browser.
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Figures update as you type. Nothing you enter leaves this tab, and no values are stored.
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Browse all specialized calculatorsAbout Fence Calculator
A fence calculator works out how many posts and sections a run of fence needs from its total length and the spacing between posts. It is the first sum of any fencing job, and the one most often got wrong by one - because a fence of N sections needs N+1 posts, not N. Getting the post count right before you dig or order saves a frustrating trip back to the yard with one hole already dug and nothing to put in it. The tool divides the length by the post spacing to get the number of sections, then adds one for the closing post. Common spacings are 6 or 8 feet depending on the panel or rail system; closer spacing is sturdier and needed in windy spots or for heavier panels. This counts posts and sections; gates, corners and end treatments add a little to the materials list and are worth allowing for separately.
Using Fence Calculator
- Measure one continuous fence run in feet. Use the manufacturer's permitted section span as the spacing input; the calculator does not choose a structurally suitable spacing.
- Read sections as the length divided by spacing, rounded up. The post count adds one end post for this open run. A 100 ft run at 8 ft spacing gives 13 sections and 14 posts.
- Sketch the final section and the locations of gates and corners before ordering. Measure each independent run and account for shared corner posts when combining their counts.
Where fence calculator helps
Before you use the result
- A fractional final section still needs space in the layout: 12 full 8 ft sections occupy 96 ft, leaving 4 ft in the 100 ft example. Confirm whether the selected panel can be trimmed or whether spacing must be redistributed.
- The plus-one rule describes an open run. A closed loop connects back to its starting post, and gates may need different posts and fittings. Do not add the results of adjoining runs without checking their shared endpoints.
- Post dimensions, footing depth, ground slope, wind exposure and permitted boundaries are not determined here. A computed count does not locate underground services or establish where a fence may be built. Use the quantity as one part of a measured installation plan.
Questions about Fence Calculator
How many posts do I need for a fence?
One more than the number of sections - a run of N sections needs N+1 posts. The tool adds that closing post automatically.
Is my data saved or uploaded?
No. Fence Calculator calculates the result entirely in this browser; the values you enter are not stored or sent to a server.
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