Fence Calculator — Free Online Tool
Fence projects stall on material math — pickets come by the piece, posts by the count, and rails by the length. This fence calculator breaks your fence line into all three with proper spacing.
What is the Fence Calculator?
Posts go every 8 feet (6 feet for high-wind areas or heavy board-on-board designs), set 2–3 feet deep in concrete. Pickets at 5.5 inches wide with a small gap mean roughly 2 pickets per foot of fence — the calculator uses your exact picket width plus a quarter-inch gap. Two horizontal rails per 8-foot section is standard; tall privacy fences often use three.
Always call 811 before digging — hitting a utility line is dangerous and expensive. Buy pressure-treated lumber rated for ground contact for posts, and add 10% extra pickets for warps and miscuts. This fence calculator assumes a straight run; for corners and gates, add one extra post per corner and gate hardware separately.
How to use this calculator
- Measure your total fence line length in feet.
- Enter your picket width (5.5" is standard).
- Click Calculate Fence for pickets, posts, and rails.
- Call 811 before you dig a single hole.
Formula
Frequently asked questions
How far apart should fence posts be?
8 feet is standard; 6 feet for high-wind areas or heavy privacy designs. This fence calculator defaults to 8.
How deep should fence posts be?
About one-third of the post height, minimum 2 feet — set in concrete for longevity.
Do I really need to call 811?
Yes — it's free, and most areas legally require utility marking before digging.
How many rails per fence section?
Two is standard; use three for 6-foot-plus privacy fences to prevent warping.