Fence Post Calculator
Find exactly how many fence posts you need for a given length and spacing.
Total posts needed
How fence post count is calculated
Every fence run is made up of sections, and every section has a post at each end. That means, for any single straight run, the number of posts is always exactly one more than the number of sections — a 1-section run has 2 posts, a 10-section run has 11 posts, and so on.
To find the number of sections, the fence length is divided by your target post spacing and rounded up to the next whole number, since you can't build a fraction of a section. That whole-number section count is then divided back into the total length to give you the actual, evenly-spaced on-center distance between posts — which will usually be slightly less than your original target spacing.
For a fence with corners, treat each straight run between corners as its own separate calculation, since the corner post is shared between two runs and shouldn't be double-counted.
Where these numbers come from
The formula and default values in this calculator are based on:
- Post-per-section counting method (sections + 1) is standard fence layout practice used throughout residential fencing installation guides.
These are planning estimates. Check your local building code, product specifications, and a licensed contractor before you buy materials or build.
Frequently asked questions
Why is the actual spacing different from what I entered?
Your fence length rarely divides evenly by your target spacing, so the calculator rounds up to a whole number of sections and then spreads the posts evenly across the full length. That even distribution is almost always slightly tighter than your original target, which keeps every section the same length.
How do I handle a fence with corners?
Calculate each straight run between corners separately, then add the results together and subtract one post for each corner shared between two runs, since a corner post belongs to both adjoining runs rather than being counted twice.
What post spacing is typical for wood fencing?
6 to 8 feet on center is common for standard wood fences. Taller or heavier fence styles, or high-wind areas, often use tighter spacing (around 6 ft) for added stability.
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