Fence Post Calculator
A solid fence starts with properly set posts. This calculator gives you the complete material list: number of posts (with correct length for embedding), concrete bags, horizontal rails, and pickets. Set posts at least 1/3 of their total length below grade — for a 6-foot fence, use 8-foot posts set 2 feet deep.
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Top Pick4×4×8 Pressure-Treated Post — Home Depot~$14.98* Affiliate links — we may earn a commission at no cost to you.
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How to Use This Calculator
- 1Enter your measurements in the fields above. Use the units shown next to each field (ft, in, etc.).
- 2Click Calculate to get your material estimate instantly.
- 3Review the highlighted result — it shows the key quantity you need to order.
- 4Use Copy Results to save your estimate, or bookmark the URL — your inputs are encoded in the link.
Pro tip: Always add 10% to your material order to account for waste, cuts, and defects.
Frequently Asked Questions
How far apart should fence posts be?
For a standard wood privacy fence, posts are set 6 or 8 feet apart. Six-foot spacing is more rigid and better for 6-foot-tall fences in windy areas. Eight-foot spacing is the most common for standard 6-foot wood fences and matches pre-cut rail lengths.
How many bags of concrete per fence post?
Plan for 2 bags of 50lb fast-setting concrete per post for a standard 4×4 post in average soil. In loose or sandy soil, use 3 bags. Posts in clay-heavy soil may need only 1–2 bags but require proper drainage to prevent rot.