Fence Calculator
Free fence calculator. Estimate posts, rails, and pickets for any fence length and post spacing — works for privacy, picket, and chain-link fences.
Quick answer
Posts needed = (fence length ÷ post spacing) + 1. Standard spacing is 8 feet for privacy fences, 6 feet for chain-link, 10-16 feet for split-rail. Pickets per section = section width × 12 ÷ (picket width + gap). Always order 5-10% extra for waste and rot.
Fence Calculator
Materials needed
How it works
Posts = (length ÷ spacing) + 1 (corners count once). Rails = sections × rails per section. Pickets account for a 3/4" gap between boards. Each post hole takes ~1.5 bags of 60 lb concrete for a typical 6 ft fence.
When to use it
Pricing materials for a privacy fence, picket fence, or chain-link install. Add 10% to lumber counts for waste and bad boards.
Common mistakes
Underestimating gates and corners. Each gate post needs to be a 4×6 (not 4×4) and set deeper. Each corner post takes more concrete because it carries load from two directions.
How the fence calculator works
Posts: total length divided by post spacing, plus 1 for the end post. Rails: 2-3 horizontal rails per section (top, bottom, sometimes middle). Pickets: section width in inches divided by (picket width + gap width), per section. The calculator handles different fence styles (privacy, picket, split-rail, chain-link) with appropriate defaults for each.
When to use it
Estimating material cost before ordering. Sizing the order so you don't run short on the day of installation. Comparing costs between styles (chain-link is cheapest, privacy fence most expensive per foot). Sanity-checking a fence contractor's quote against actual material counts.
Common mistakes
- Forgetting gates. Each gate adds material costs (heavy-duty hinges, latches, drop-rod hardware) and changes the post layout. Plan gate locations before counting posts.
- Ignoring slope. Sloped yards need stepped or racked installations, which use more linear feet of fencing than the property line distance suggests. Walk the line with a measuring wheel, not from a flat plan view.
- Underestimating waste. Privacy fence pickets often have warps, knots, or splits — 5-10% extra is standard. Cedar warps more than pressure-treated; account for it in the order.
Frequently asked questions
How many fence posts do I need?
Total fence length divided by post spacing, plus 1 for the end. For a 100-foot privacy fence with 8-foot spacing: (100 ÷ 8) + 1 = 13.5 → 14 posts. Round up; you'd rather have an extra than be short.
How far apart should fence posts be?
8 feet is standard for wood privacy fence. 6-10 feet for chain-link. 10-16 feet for split-rail. Closer spacing means a sturdier fence but more material; wider spacing is cheaper but sags over time.
How deep should fence posts go?
1/3 of the post's length below grade, with a minimum of 30 inches in cold climates (below frost line). For a 6-foot-tall privacy fence, that's an 8-foot post buried 2.5-3 feet. Set in concrete for permanence; tamped gravel for replaceable.