Fence Calculator
Estimate the number of posts, rails, and pickets needed for your fence project.
How the Fence Calculator Works
Posts: Total length ÷ post spacing, plus 1 for the end post. Example: 100 ft fence with 8 ft spacing = (100 ÷ 8) + 1 = 14 posts.
Rails: (Posts − 1) spans × number of rail rows per span.
Pickets: Total linear feet × 12 ÷ (picket width in inches). This gives the number of pickets for a zero-gap privacy fence. Subtract as needed if you want gaps between pickets.
Common Fence Post Spacing
| Fence Type | Post Spacing | Rail Rows |
|---|---|---|
| Wood privacy (6 ft) | 6–8 ft | 2–3 |
| Picket / decorative | 6–8 ft | 2 |
| Split rail | 8–10 ft | 2–3 |
| Chain-link | 10 ft | 1–2 |
| Post-and-rail (farm) | 8–10 ft | 3–4 |
Frequently Asked Questions
How far apart should fence posts be?
Standard fence post spacing is 6–8 feet on center for wood privacy fences. Six-foot spacing provides better support and is recommended for tall fences (6+ ft) or areas with high winds. Eight-foot spacing is common for shorter decorative fences. Metal fence posts for chain-link are typically 10 feet apart.
How deep should fence posts be set?
The standard rule is to bury one-third of the post's total length underground. For a 6-foot fence with 8-foot posts, bury 2–2.5 feet. For frost-prone areas, posts should extend below the frost line (often 3–4 feet deep in northern climates) to prevent heaving.
How many rails does a wood fence need?
A standard 6-foot privacy fence uses 2–3 horizontal rails. Two rails are minimum (top and bottom), while three rails are recommended for fences over 5 feet tall for added strength and stability. Picket fences and short decorative fences typically use 2 rails.
What width pickets should I use?
Common wood fence picket widths are 3.5 inches (2×4) and 5.5 inches (2×6). Pickets are typically installed with a small gap between them — 0 for privacy fences, or 1–3 inches for semi-privacy or decorative fences. This calculator accounts for picket width to compute the total count needed.
Do I need a permit to build a fence?
Many municipalities require permits for fences over a certain height (often 4–6 feet) or for fences built within a certain distance of property lines. Always check local zoning ordinances and HOA rules before starting a fence project. Utility line locates (Call 811 in the US) are required before digging post holes.