Fence Calculator
Work out exactly how many posts, panels or pickets, rails and bags of concrete you need for a fence line — including yards with multiple sides or a gate. Add your own prices for a full cost estimate.
How this calculator works
Posts and rails are worked out per side of the fence, then summed — this matters for yards with corners, since each straight run needs its own start and end post:
for each side: sections = ceil( side length ÷ post spacing ) posts = sections + 1 total posts = sum of posts across all sides total rails = sum of sections × rails per section concrete = total posts × bags per post
Panels or pickets are also totalled per side before the gate allowance is subtracted, so a panel or picket run never spans across a corner into the next side.
Worked example
A single 100 ft side, 8 ft post spacing, pre-built 8 ft panels, one gate, a 6 ft fence with 3 rails per section:
- Sections: 100 ÷ 8 = 12.5 → 13 sections. Posts: 13 + 1 = 14 posts.
- Panels: 100 ÷ 8 = 12.5 → 13, minus 1 gate = 12 panels.
- Rails: 13 sections × 3 = 39 rails.
- Concrete: 14 posts × 2 bags = 28 bags.
Choosing post spacing and rail count
| Fence height | Rails per section | Typical post spacing |
|---|---|---|
| Up to 4 ft | 2 | 8 ft |
| 5–6 ft | 3 | 8 ft |
| Over 6 ft, or heavy wind exposure | 3–4 | 6–8 ft |
Vinyl and pre-built panel systems are often designed around a fixed panel width — check the product's actual panel size before assuming standard 8 ft spacing, since matching post spacing to the panel size avoids awkward cut panels at the end of a run.
Corner, end and gate posts
This calculator counts every post the same way, but in practice corner, end and gate posts carry more load than the line posts in between them — resisting the pull of the fence fabric or the swing of a gate. It's common to use a larger post size and a deeper, wider concrete footing at these positions even though the material count treats them identically.
Frequently asked questions
What is the standard post spacing for wood vs vinyl fencing?
Wood fence posts are commonly spaced 8 feet apart, matching standard panel and rail lengths. Vinyl fencing often uses the same spacing, though some vinyl panel systems are built for 6 or 8 foot sections specifically, so check your product's panel size first.
How much concrete does a fence post need?
A typical residential post uses about two 60 lb bags of concrete per hole, though this varies with post size, hole depth and soil conditions. Corner, end and gate posts often carry more load and may need a larger footing than standard line posts.
How many rails does a 6 ft fence need?
A fence up to about 4 feet tall typically uses two rails per section. Fences around 6 feet or taller commonly use three rails per section, adding a middle rail for extra rigidity and less panel flex.
Do corner and end posts need anything different from line posts?
Corner, end and gate posts typically carry more load than line posts, since they resist the pull of the fence and any gate hardware. It's common to use a larger post size and a bigger, deeper footing here, even though this calculator counts every post the same way.