Fence Picket Calculator
Count the pickets, posts and rails for a wood fence from its length, picket width, gap and post spacing.
How it works
pickets = ⌈length in inches ÷ (picket width + gap)⌉ · sections = ⌈length ÷ post spacing⌉ · posts = sections + 1 · rail feet = length × rails per section
Each picket plus its gap consumes a fixed slice of the run, so the picket count is the fence length in inches divided by that slice, rounded up. Posts sit at the ends of each section, so a fence has one more post than it has sections. Rails span between posts along the whole length once per rail, so rail material is simply the fence length times the number of rails you run.
Worked example
A 100 ft privacy fence with 5.5 in pickets butted tight (0 gap): 1,200 in ÷ 5.5 = 218.2, rounded to 219 pickets. At 8 ft post spacing that is 100 ÷ 8 = 12.5, rounded to 13 sections and 14 posts, with 2 rails giving 200 ft of rail.
Frequently asked questions
How far apart should fence posts be?
Six to eight feet is standard. Eight-foot spacing uses fewer posts and holes but needs stiffer rails to avoid sagging; six-foot spacing is stronger and better for tall privacy fences exposed to wind.
How many rails do I need?
Two rails suit fences up to about 5 ft, one near the top and one near the bottom. Add a third middle rail for 6 ft privacy fences to keep the pickets from bowing and to give them more fastening points.
Should I leave a gap between pickets?
A solid privacy fence butts pickets tight, though a small gap allows for expansion. Picket or "spaced" fences deliberately leave a gap — often equal to a picket width — which roughly halves the picket count.
Related calculators
Estimates only — add for waste and confirm against local building codes and supplier specs.