Fence Post Spacing Calculator.
Divide a straight fence run into equal sections without exceeding the maximum center-to-center post spacing you enter. Get the post count, exact spacing and every center position.
Fence run
Find the fewest equal sections that stay at or below your maximum spacing.
Used only to show the clear opening between post faces.
Post spacing
Enter the straight fence run and your maximum allowed spacing.
How many fence posts do I need?
Enter the total straight fence run and the maximum center-to-center spacing you want to allow. The calculator uses enough equal sections to keep every section at or below that maximum, then adds the two end posts to get the total post count.
Because the run is divided evenly, you avoid finishing with one short or awkward final bay. The exact center-to-center spacing is the measurement to repeat from one post center to the next.
Center-to-center spacing vs clear opening
Fence spacing is commonly laid out from post center to post center. If you also enter the post width, the calculator shows the approximate clear opening between the faces of adjacent posts.
Use the center positions for setting out the run. The clear opening is useful when checking whether panels, rails or infill will fit, but the calculator does not choose hardware or structural spans for you.
When a straight-run calculation is not enough
Gates, corners, changes in direction, slopes and fixed end points can require extra or differently positioned posts. Treat each straight uninterrupted run as its own layout when those features break the fence line.
Your maximum spacing should come from the fence system, panel size, local requirements or your project design. This calculator divides the geometry; it does not set a structural maximum spacing.
Frequently asked questions
How do I calculate fence post spacing?
Enter the fence run and the maximum center-to-center spacing. The calculator finds the minimum number of equal sections needed and divides the run evenly between them.
How many posts do I need for a straight fence run?
For one uninterrupted straight run, the calculator returns the total post count including both end posts after it determines the required number of equal sections.
Why is the exact spacing smaller than my maximum spacing?
The maximum is a limit, not a target that must be hit exactly. The run is divided into equal sections, so the final spacing is often slightly smaller to make every bay the same width.
What is center-to-center fence post spacing?
It is the distance from the center line of one post to the center line of the next. This is the main spacing value returned by the calculator.
Can I calculate the clear gap between post faces?
Yes. Enter the post width and the calculator subtracts it from the center-to-center spacing to show the clear opening.
Does this include gates and corner posts?
No. The calculator models one straight uninterrupted run. Gates, corners and other fixed features should be handled as boundaries between separate runs.
Does the calculator tell me the safe maximum post spacing?
No. Enter the maximum spacing appropriate for your fence system or project. The tool only creates an equal layout that stays within the limit you provide.