Formula
Picket count = ceil((run + maximum gap) ÷ (picket width + maximum gap)); actual gap is recalculated from the resulting count.
Fence Picket Spacing Calculator
Find a whole picket count, the actual gap, and center-to-center spacing for a fence run.
How this fence picket spacing estimate works
Picket layouts are a balance between a maximum gap and a clean repeat. This tool rounds the count up first, then reports the gap that the chosen count actually produces.
Worked example
A 96 inch run with 3.5 inch pickets and a 2 inch maximum gap produces 18 pickets and an actual gap of about 1.94 inches.
Before you buy
Allow for the space taken by posts, rails, end setbacks, and any gate opening before treating the run as a finished picket field.
Assumptions
Defaults are starting points. Replace coverage, density, package yield, spacing, and allowance values with the product or plan you are actually using.
Limitations
This is a straight-run spacing estimate. It does not lay out posts, rails, caps, gates, slopes, or decorative patterns.