Fence Calculator
Posts & panels for a fence run
Building a fence? Enter the total run length to estimate the posts, panels and bags of concrete you need to set the posts, at standard 8-foot spacing.
Posts and panels
With 8-foot sections you need one post per section plus one to close the run, and one panel per section. For each section, plan 2–3 rails. Set posts in concrete — plan about one to two 50 lb bags of fast-setting mix per hole; the calculator estimates two bags per post, a safe figure for a typical 4×4 post in a 10–12 inch hole.
How deep to set posts
Bury posts at least ⅓ of their above-ground height, and always below your local frost line so they don't heave in winter — typically a 2-foot-deep hole for a 6-foot fence. Set the corner and end posts first and string a line between them so every post in between lines up straight.
Gates and sloped ground
Add a sturdier post on each side of every gate; gates sag over time, so heavier posts and a diagonal brace pay off. On a slope you can either "rack" panels to follow the grade or "step" them down in level sections — stepping looks cleaner but leaves triangular gaps at the bottom.
Fence Calculator: frequently asked questions
How far apart should fence posts be?
Commonly 6–8 feet on center. Closer spacing makes a stronger fence.
How much concrete per fence post?
Roughly one to two 50 lb bags of fast-setting concrete per post hole, depending on hole size.
How deep should fence post holes be?
Dig holes about one-third of the post's above-ground height and below the frost line — commonly 2 feet deep, roughly 3× the post width across. Deeper, wider, concrete-filled holes give the most wind-resistant fence.