Fence Calculator
Posts, rails, pickets and concrete bags for a fence run from its length, your post spacing, gates and board size — layout arithmetic, no spacing rules assumed.
How many posts, rails and pickets a run needs, the equal spacing that fits, and the bags of concrete at the rate you enter — with every count shown as a formula.
Example: 120 ft with one 4 ft gate at 8 ft spacing: 15 sections of 7.73 ft, 17 posts, 30 rails (232 ft) and 232 pickets of 5.5 in with a 0.5 in gap.
Sections first,
then everything else.
How a run becomes sections and posts, what gates do to the count, how pickets are counted, and the rules this page deliberately does not decide for you.
Sections and posts
The fenced length (total minus gates) is divided into whole sections at your post spacing, rounding up; the page then spreads the sections evenly so there is no short end section, and says what the actual spacing became. Posts are sections plus one, and each gate adds one post (a gate has two posts, one of which is shared with the run). Corners, changes of direction and slopes need posts you add yourself.
Rails and pickets
Rails are sections times the rails per section you choose. Pickets are the fenced length divided by one board width plus one gap, rounded up — the same arithmetic whether the boards are wood, composite or metal. For a panel, wire or chain-link fence, set the picket width to 0 and count panels as sections.
Concrete and waste
Bags per post are your figure (0 = not counted): the number depends on post size, hole diameter and depth, which the page does not know. Waste is a percentage you choose and applies to rails and pickets; none is assumed.
What the number does not settle
Maximum post spacing, embedment depth, wind exposure, gate hardware and property-line setbacks are matters of local rules and the fence maker's instructions — the page deliberately carries no such figures. Inputs stay in your browser; the same four anonymous usage counts as the rest of the site apply.