Vinyl Fence Calculator — Posts, Panels & Rails

Formula

How this is calculated

Posts are spaced evenly along the run. For an open straight run the number of bays equals the total length divided by the post spacing (rounded up), and there is always one more post than bays — a run with N bays needs N + 1 posts, one at each end and one at every internal junction. For a closed perimeter loop, the first and last post are the same, so the post count equals the number of bays.

Panels are the pre-built sections that span between posts. Dividing total length by the panel width and rounding up gives the panel count. Rails are the horizontal members inside each section: fences up to 4 ft tall typically use 2 rails per section, while taller fences use 3 for rigidity and to satisfy most building codes. Post caps sit on top of each post for a finished look — one per post. The picket count assumes standard 3½-inch tongue-and-groove vinyl boards for privacy-style panels.

All inputs must use the same unit (feet here). For real projects add 5–10% to panel and picket orders for offcuts and breakage, and check local codes for height restrictions and setback requirements. Vinyl posts require a steel sleeve insert set in concrete for structural integrity — the insert and concrete are not counted here.