Fence Calculator
Estimate number of posts and fence sections from total fence length.
Estimate number of posts and fence sections from total fence length.
A fence length calculator turns the total length of a planned fence into a count of fence sections and posts. A section is the span between two posts, usually filled with a pre-built panel, pickets on rails, or a stretch of chain-link fabric. Because every section needs a post at each end, a straight fence always needs one more post than it has sections. Knowing both numbers before a trip to the supplier helps with ordering posts, panels or rails, concrete, and hardware.
Post spacing has the biggest effect on the count. Wood privacy fences are usually built with posts 6–8 feet on center, rail fences 8–12 feet, and chain-link around 10 feet. Tighter spacing adds strength against wind and sagging but uses more posts and more concrete. The shape of the fence matters too: corners, gates, and changes in direction each need a post at a fixed location, so a fence with several turns usually needs a few more posts than one straight run of the same total length. Measure along the actual fence line rather than estimating from a lot size, and check local rules on height and setbacks before finalizing the layout.
To use this tool, enter the total fence length in feet and the post spacing in feet (8 feet by default). The calculator divides length by spacing, rounds up to the next whole section so no span is longer than your chosen spacing, then adds one end post. The result shows the estimated number of posts and sections. For example, 100 feet at 8-foot spacing gives 13 sections and 14 posts. Add posts for gates and corners as described in the questions below, since the estimate assumes one continuous straight run.
6–8 feet on center for wood privacy fences; 8–12 feet for rail fences.
The calculator includes end posts. Add extra for corners and gates.
Results are estimates for planning purposes. Verify with product labels and local requirements before purchasing materials.
Divide your total fence length by the post spacing to get the number of sections. Add one post for the final end post. Gates require additional posts on either side.
| Fence length | 6 ft spacing | 8 ft spacing | 10 ft spacing |
|---|---|---|---|
| 50 ft | 10 posts | 8 posts | 7 posts |
| 100 ft | 18 posts | 14 posts | 12 posts |
| 150 ft | 26 posts | 20 posts | 16 posts |
| 200 ft | 35 posts | 26 posts | 21 posts |
At 8-foot spacing: 100 ÷ 8 = 12.5 sections, round up to 13 sections, plus 1 end post = 14 posts. At 6-foot spacing: 17 sections + 1 = 18 posts.
6–8 feet on center for wood privacy fences. 8–12 feet for rail fences. 10 feet for most chain-link fences.
One-third to one-half of the post length should be buried. For a 6 ft privacy fence, use 8 ft posts set 2–2.5 ft deep.
For most privacy and structural fences, yes. Use 1–2 bags of quick-set concrete per post. Light decorative fences may not require concrete.
6–8 feet on center. Closer spacing increases strength. Wider spacing reduces material cost but may make panels look saggy.
At 8-foot spacing, 150 ÷ 8 = 18.75, which rounds up to 19 sections and 20 posts. At 6-foot spacing, 150 ÷ 6 = exactly 25 sections and 26 posts.
Calculate each straight side separately, round each side's sections up, then add the sections together and add 1 post for an open-ended fence. For sides of 50, 100, and 50 feet at 8-foot spacing, that is 7 + 13 + 7 = 27 sections and 28 posts, two more than the 26 posts a single 200-foot run would need.
Each gate needs a sturdy post on both sides, and the gate opening replaces a regular section. The simplest approach is to treat the gate as a break in the fence: calculate the runs on either side of the gate separately, then add their post counts.