Picket count depends on picket width and the gap you leave between them — a spaced picket fence uses far fewer than a tight privacy run. This view takes fence length and picket width to count pickets per section and overall.
Field notes
Set your corner and end posts first, string a line between them, and space the rest to that line — eyeballing post spacing leaves a fence that waves. Dig post holes about a third of the post height deep and below your frost line, or a winter heave will lift them. Budget one to two bags of fast-setting concrete per post; the calculator counts sections, but the hole depth is what holds the fence up.
How the fence pickets calculator works
The math behind the tool:
posts = ceil(length ÷ spacing) + 1
sections = posts − 1Sources: American Wood Council (wood post and rail spans).