Fence Calculator

Posts, rails, and pickets

A fence is three parts, and each one keys off a different number. Posts are set by your spacing: divide the run by the post spacing and add one for the closing post. Most wood fences sit on 6 to 8-foot centers — closer spacing is sturdier and costs more posts and concrete.

Rails (the horizontal stringers) run between posts. A 6-foot privacy fence usually carries three rails; a shorter fence two; an 8-foot fence four. Multiply rails-per-section by the number of sections.

Pickets are pure division: the run in inches divided by one picket's width plus the gap. For a solid privacy fence, set the gap to zero. For a classic spaced picket look, a 2–3 inch gap stretches the same boards over more wall.

Don't forget the concrete

Each post wants a hole one-third of the post's above-ground height deep — roughly 2 feet for a 6-foot fence — and a couple of bags of fast-setting concrete to anchor it. That's two numbers the picket count won't show you, so plan on about two 50-lb bags per post and a gravel base at the bottom of each hole for drainage. Set your corner and gate posts first, run a string line, and space everything off that line.