How this fence calculator works
A wood fence is four orders in one — posts, rails, pickets, concrete — and they all fall out of the run length and the post spacing:
pickets = length ÷ (picket + gap) × (1 + waste) · rails = sections × 3 over 4′ tall, × 2 under
Worked example: materials for 100 feet of fence
100 ft of 6 ft privacy fence at 8 ft on center breaks into 13 sections — 14 posts, 39 rails (three per section at this height), and 230 pickets of 5.5 in with 5% waste. Two bags of concrete under each post adds 28 bags; at the default prices the whole order lands around $1,726.
How many fence posts and rails do I need?
| Run | Posts | Rails | Pickets | Concrete |
|---|---|---|---|---|
| 50 ft | 8 | 21 | 115 | 16 bags |
| 100 ft | 14 | 39 | 230 | 28 bags |
| 150 ft | 20 | 57 | 344 | 40 bags |
| 200 ft | 26 | 75 | 459 | 52 bags |
| 300 ft | 39 | 114 | 688 | 78 bags |
| Picket style | Count |
|---|---|
| Privacy — 5.5″ butted, no gap | 230 |
| Spaced — 5.5″ with 1.75″ gap | 174 |
| Spaced — 3.5″ with 3.5″ gap | 180 |
Fence FAQ
How many fence posts do I need for 100 feet?
14 at 8 ft on center — 13 sections plus one post to close the run. Tighten to 6 ft spacing and it becomes 18. Corners and gates each take a post of their own, so walk the line and count every change of direction before ordering.
How far apart should fence posts be?
6 or 8 ft on center for a wood fence. 8 ft saves posts and concrete and suits standard 8 ft rails; 6 ft is stiffer and the better call for a 6 ft privacy fence in wind. Don’t stretch past 8 ft — rails sag and pickets loosen.
How deep should fence posts be set?
About a third of the fence height and never less than 2 ft, always below the local frost line — a 6 ft privacy fence wants 8 ft posts set roughly 2 ft into a hole three times the post width. Gate posts go deeper, in extra concrete, because they carry all the swing load.
How many pickets do I need for 100 feet of fence?
230 in solid privacy style — 5.5 in faces of 1×6 pickets butted tight, with 5% waste folded in. Space 3.5 in pickets with a 3.5 in gap and the same run takes 180; the gap does part of the covering.
How much concrete per fence post?
Two 80 lb bags per line post is the working figure for a 6 ft fence in a 10 in hole — 28 bags across the default 100 ft run. Use three at gates, corners and ends, and set the bags-per-post field to whatever your hole size actually takes.
How much does it cost to build a wood fence?
About $17 per foot in materials at the default prices — $1,726 for 100 ft of 6 ft privacy fence: $920 in pickets, $252 in posts, $351 in rails, $203 in concrete. Hired out, wood privacy fence commonly quotes at $25–55 per foot installed in 2026.
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