Quick Answer: For a standard 6-foot wood privacy fence, plan on one post every 8 feet, two to three horizontal rails per section, roughly 1.1 pickets per linear foot (5.5″ boards with a small gap), and one to two 50 lb bags of concrete per post hole. A 150-foot fence usually needs about 20 posts, 40 rails, and 160–170 pickets. Use the calculator below to get exact numbers for your yard.
Key Takeaways
- Post spacing (usually 6–8 feet) is the number that drives almost every other material count, so get it right first.
- Board width and gap size change your picket count more than most people expect — even a half-inch difference adds up over 100 feet.
- Post length isn’t just fence height. You need to add burial depth, which is typically about one-third of the post’s height above ground.
- Wood fence materials alone (before labor) usually run $10–$30 per linear foot, depending on wood species and style. Chain link materials are cheaper, vinyl runs higher.
- Always buy 10% extra lumber for cuts, warped boards, and mistakes. Nobody regrets the extra bundle; everybody regrets the second trip to the lumberyard.
I’ve built enough fences to know the math looks simple until you’re standing in the lumber aisle trying to remember if you need 2 rails or 3, and whether that gate post counts as one of your regular posts or an extra one.
It doesn’t help that every fence calculator online assumes you’re building the exact same style they picked. So I built this one to actually match how DIY fences get built — pick your style, punch in your numbers, and get a real materials list.
Plug in your fence length, height, style, and post spacing, and the calculator will give you posts, rails, pickets, and concrete — plus a rough materials cost range.
How the Numbers Are Calculated
If you want to sanity-check the calculator (or do it by hand), here’s the logic behind each number.
Posts
Posts = (fence length ÷ post spacing) + 1, rounded up. Add one extra post for each gate, since a gate needs a post on both sides and one of those is usually shared with the regular line.
Most residential wood fences use 8-foot spacing. Windier regions or taller fences (7–8 ft) do better with 6-foot spacing, since it cuts down on rail flex and racking.
Post Length
This trips people up. Your post length is not the same as your fence height. You need to bury roughly one-third of the post underground for stability — more in frost-prone climates, where the hole needs to go below the frost line.
A 6-foot-tall fence typically needs an 8-foot post (6 ft above ground + roughly 2 ft buried). An 8-foot fence usually needs a 10 or 12-foot post.
Rails
Rails are the horizontal boards that pickets or panels attach to. As a rule of thumb:
- Fences up to 4 ft tall: 2 rails per section
- Fences 5–6 ft tall: 2–3 rails per section
- Fences 7–8 ft tall: 3–4 rails per section
Sections = number of posts minus 1. Multiply by rails-per-section to get your total rail count, then convert to linear footage based on your post spacing (each rail run is roughly one section wide).
Pickets or Boards
Picket count = fence length (in inches) ÷ (board width + gap width). A standard 5.5″ board (actual width, not nominal) with no gap for a privacy fence gets you close to 2.2 boards per linear foot. Add a 1–2″ gap for a semi-privacy or picket look, and that number drops.
Concrete
Most DIY posts use one to two 50 lb bags of concrete per hole, depending on hole diameter and post size. A 4×4 post in a 10″-diameter, 24″-deep hole typically takes about 1.5 bags. Corner and gate posts, which carry more load, often get an extra bag.
Materials by Fence Style
| Fence Style | Posts | Rails per Section | Boards/Pickets | Typical Material Cost (per linear ft) |
|---|---|---|---|---|
| Wood Privacy (6 ft) | 8 ft spacing | 2–3 | ~2.2/ft (butted boards) | $10–$30 |
| Wood Picket (3–4 ft) | 8 ft spacing | 2 | ~1.0–1.3/ft (2″ gaps) | $10–$20 |
| Ranch / Split-Rail (3–4 rail) | 8–10 ft spacing | 3–4 (no pickets) | None | $8–$18 |
| Chain Link | 10 ft spacing | N/A (top rail only) | N/A | $5–$15 |
| Vinyl Privacy | 8 ft spacing | Pre-assembled panels | Pre-assembled panels | $15–$30 |
Material cost ranges reflect current national averages and don’t include labor, gates, or hardware. Wood fence material prices generally run $10 to $30 per linear foot, and chain link fencing averages $5 to $15 per linear foot installed with materials making up a portion of that. Vinyl runs higher upfront but needs no staining or sealing.
Step-by-Step: Calculating Materials by Hand
- Measure your fence line. Walk it with a measuring wheel or tape, and note where corners and gates fall.
- Decide post spacing. 8 feet is standard; drop to 6 feet for taller or windier runs.
- Calculate posts. (Length ÷ spacing) + 1, plus one per gate.
- Pick post length. Fence height + burial depth (about a third of the height, more if you’re below the frost line).
- Count rail sections. Posts minus 1. Multiply by rails-per-section for your style and height.
- Calculate pickets. Fence length in inches ÷ (board width + gap).
- Add concrete. 1–2 bags per post, more for corners and gates.
- Add 10% to your lumber order for waste, warped boards, and cutting errors.
Frequently Asked Questions
How much lumber do I need for a 100-foot fence? For a standard 6-foot privacy fence at 8-foot post spacing, expect around 13–14 posts, 24–26 rails, and 210–220 pickets (5.5″ boards, butted). Add 10% for waste.
How many bags of concrete per fence post? Most 4×4 posts in a standard 24″-deep hole take 1–2 bags of 50 lb quick-setting concrete. Larger posts, corner posts, and gate posts often need 2.
What post spacing should I use? 8 feet is the standard for most residential wood fences. Drop to 6 feet for fences over 6 feet tall or in high-wind areas.
Do I need more rails for a taller fence? Yes. Fences up to 4 feet generally need 2 rails; 6-foot fences do better with 3; 8-foot privacy fences often need 4 to prevent sagging and racking.
How much extra material should I buy? Add 10% to your picket and rail order to cover cuts, warped boards, and mistakes. It’s cheaper than a second trip to the lumberyard.
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