Fence Calculator (Posts, Rails & Pickets)

A fence run is divided into equal-width sections, each no wider than the maximum post spacing you'd want between posts — rather than using a fixed spacing and leaving a short, mismatched final gap, this calculator spreads the posts evenly: the number of sections is the smallest whole number that keeps every section at or under your maximum spacing, sections = ceil(fenceLength ÷ maxPostSpacing), which needs sections + 1 posts and gives an actual spacing of fenceLength ÷ sections — always at or under what you asked for. Rails scale directly with the number of sections (your chosen rails-per-section count × the number of sections).

Picket count is a standard start-aligned packing calculation: the first picket takes up its own width, and every picket after that adds one gap plus one more picket width, so the number that fit end-to-end along the run is floor((fenceLength − picketWidth) ÷ (picketWidth + picketGap)) + 1.