Fence Calculator
Enter your fence length. Get the posts, rails and pickets to buy.
100% in your browser - no upload, no sign-up.
Materials needed
Posts
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Sections
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Rails
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Pickets
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💡 Keep a few spare pickets - boards warp and split.
⚠️ Buy longer posts - a 6 ft fence needs 8 to 9 ft posts.
How to use this fence calculator
- Enter your total fence length in feet, and the gate width if you're leaving an opening.
- Set the post spacing and fence height - 8 ft spacing and 6 ft height are typical for a wood fence.
- Read off the posts, rails and pickets. Open Advanced to tune picket width, gap and waste to match your boards.
How the fence materials are counted
Posts come from the run divided by the post spacing, plus one for the closing end: posts = length ÷ spacing + 1. Eight feet is the typical post spacing for a wood fence - tighter spacing costs more posts but stiffens the run. Rails are sized by height, one rail for every 24 inches of fence with a minimum of two, so a 6 ft fence gets three rails per section. Pickets are the run divided by one board's coverage: pickets = run ÷ (picket width + gap), and the gate width is taken out of the run first since you don't picket the opening. Because boards split and cull, the picket count adds a 10% waste margin by default - change it to match your lumber.
Frequently asked questions
- How many fence posts do I need?
- Divide your fence length by the post spacing and add one for the end post. At the typical 8 ft spacing, a 100 ft fence is 100 ÷ 8 = 13 sections, so 14 posts. Corner posts and gate posts are extra, so add one wherever the fence turns or a gate hangs.
- How far apart should fence posts be?
- Six to eight feet on center is standard for a wood fence, and 8 ft is the most common because it matches pre-cut rail and panel lengths. Use tighter 6 ft spacing on tall or windy runs for a stiffer fence, and don't exceed 8 ft with standard rails or they'll sag over time.
- How many pickets per section?
- Divide the section width by one picket's coverage - the picket width plus the gap between boards. An 8 ft (96 in) section with 5.5 in pickets butted tight is 96 ÷ 5.5 ≈ 18 pickets; add a small gap and it drops to about 16. This calculator does that across the whole run and adds a waste margin on top.
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