Estimates for planning only. Always confirm measurements and order a little extra for waste and cuts.
How the fence calculator works
This calculator turns your total fence length and post spacing into the posts, sections, rails, and concrete you'll need, so you can price a project or plan materials.
The formula
Posts and sections come from the run length divided by your post spacing, plus an extra post to close each run and one per gate:
Sections = length ÷ post spacing (rounded up)
Posts = sections + 1 + gates · Rails = sections × rails per section
Post spacing and rails
Eight feet is the most common post spacing because rails and panels are typically sold in 8-foot lengths. Six-foot spacing makes a sturdier fence for tall privacy panels or windy sites. Privacy fences usually use three rails per section; ranch and picket styles often use two. Plan one to two bags of concrete per post for a solid set.
Pro tips
- Set posts in concrete at least one-third of their above-ground height deep, and below your frost line.
- Order one or two extra posts, snapped or out-of-plumb posts happen.
- Gates need their own hardware (hinges, latch) and a sturdy post on each side.
- Call 811 to locate underground utilities before you dig. Always.
Frequently asked questions
How far apart should fence posts be?
Eight feet on center is standard and matches common rail and panel lengths. Drop to 6 feet for tall privacy fences or very windy areas.
How many posts for a 100-foot fence?
At 8-foot spacing, about 13 sections, so roughly 14 line and end posts, plus one more for each gate.
How much concrete per fence post?
Plan one to two 50 lb bags per post depending on post size and hole depth. Bigger posts and taller fences need more.
How deep should fence posts go?
At least one-third of the post's above-ground height, and below your local frost line so they don't heave in winter.
Does this include pickets or panels?
It sizes posts, sections, rails, and concrete. Picket or panel counts vary by style and spacing, so add those based on your chosen product.
