Fence post & picket spacing conventions

A fence take-off starts from a few spacing conventions: posts every ~8 ft, a nominal 1×6 picket 5.5 in wide with a ~1/4 in gap, and 2 rails per section (3 for tall privacy fences). The values below are labeled planning conventions you can adjust to your design. Use them in the fence-materials tool.

ConventionTypical valueUsed for
Post spacing8 ft on centerSections = length ÷ spacing; posts = sections + 1
Picket width5.5 inA nominal 1×6 picket is 5.5 in wide
Picket gap0.25 inPickets = length (in) ÷ (width + gap)
Rails per section22 for most fences, 3 for tall privacy

Labeled planning conventions you can adjust to your design — add posts for gates and corners.