Garden Fence Posts Calculator
Count the posts, sections and rails for a garden fence from its length, your post spacing and the number of gates.
How it works
Line posts = ⌈length ÷ spacing⌉ + 1 · Posts = line posts + gate posts · Sections = posts − 1 · Rails = sections × rails per section
A straight fence run needs one more post than it has sections, because both ends are capped. Dividing the length by your on-center spacing and rounding up gives the sections; add one to close the run, plus an extra post for each gate opening. Most panel and rail fences use 6–8 ft spacing, and each post typically takes about two bags of fast-setting concrete depending on hole size.
Worked example
For 100 ft of fence at 8 ft spacing: ⌈100 ÷ 8⌉ + 1 = 14 line posts. Adding one gate post gives 15 posts, 14 sections, and — at 3 rails per section — 42 rails.
Frequently asked questions
How far apart should garden fence posts be?
Six to eight feet on center is standard. Closer spacing makes a stiffer, stronger fence and is worth it in windy sites or for heavy panels; 8 ft is the common maximum for most residential fencing.
How much concrete does each post need?
A typical 4×4 post in a 10-inch-wide hole about 2 feet deep uses roughly two 50 lb bags of fast-setting concrete. Bigger posts, wider holes or deeper frost lines increase that.
How deep should fence posts be set?
Bury about one-third of the post length, and at least below your local frost line. For a 6 ft fence that usually means an 8 ft post set about 2 feet deep, deeper for gate and corner posts.
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This calculator is for educational purposes. Double-check important results before acting on them.