Privacy Fence Calculator: Materials & Cost for a 6-Foot Fence

A 6-foot privacy fence is the most popular fence in America — and the one with the most confusing material math. Here's how to count every board, post, and bag of concrete, plus what it'll cost.

How the material math works

For a standard 6-ft privacy fence with posts every 8 feet:

Posts: (fence length ÷ 8) + 1, then round up. A 100-ft run = 13.5 → 14 posts. Add 1–2 extra for each gate (gate posts should be 6×6, not 4×4).

Pickets: A 6-inch-wide picket covers about 5.5 inches once you account for the gap. Formula: (length in inches ÷ 5.5), or roughly 22 pickets per 10 linear feet. A 100-ft fence ≈ 218 pickets — buy 230 to cover splits and bad boards.

Rails: 2 rails per 8-ft section (3 for extra-stiff fences or high-wind areas). 100 ft = 12.5 sections → 26 rails (2×4 × 8 ft).

Concrete: one 50-lb bag per post for a standard 3-ft-deep hole in decent soil — 14 bags for our example. Rocky or sandy soil: go 1.5 bags per post.

Material list: 100-ft cedar privacy fence

| Material | Quantity | Approx. cost | |---|---|---| | 4×4 × 8 ft posts | 14 | $200–$350 | | 1×6 × 6 ft cedar pickets | 230 | $1,200–$1,800 | | 2×4 × 8 ft rails | 26 | $150–$250 | | 50-lb concrete bags | 14 | $70–$100 | | Screws, hardware | — | $80–$150 | | Stain/sealer | 5 gal | $150–$250 | | Materials total | | ~$1,850–$2,900 |

Cost per linear foot by material (installed)

| Material | Per linear foot | 100 ft (approx.) | |---|---|---| | Pressure-treated pine | $20–$40 | $2,000–$4,000 | | Cedar | $30–$55 | $3,000–$5,500 | | Vinyl (PVC) | $45–$70 | $4,500–$7,000 | | Composite | $50–$90 | $5,000–$9,000 |

DIY saves roughly 40–50% — you pay materials only, which is the table above minus labor.

The decisions that change the price

1. Picket style.

• Board-on-board: pickets overlap, zero gaps, best privacy — uses ~25% more pickets
• Shadowbox: alternating sides, looks good from both — ~15% more pickets
• Standard side-by-side: cheapest, small gaps appear as wood shrinks

2. Post depth and size. Code in frost areas usually wants posts below the frost line — 3 to 4 feet deep in the northern US. That's longer (pricier) posts and more concrete per hole. Corner and gate posts should always be 6×6.

3. Gates. Each walk gate adds $150–$400 in materials alone (heavier posts, hinges, latch). Plan gate locations before you buy — moving a gate later means moving posts.

4. Terrain. A slope means stepped panels (more cutting, more waste) or racked panels (pricier). Rocky soil can double your concrete use and your digging time.

5. Permits and HOA. Most cities require a fence permit ($50–$200), and many cap backyard fences at 6 ft — front yards often 4 ft. HOAs may dictate material and style. Check before buying.

The 5 mistakes that cost the most

1. Posts too shallow. The #1 fence killer. In frost country, shallow posts heave within two winters.
2. Setting posts in dry concrete mix. Pour the mix dry and "let ground moisture cure it" is a myth — always add water and mix.
3. Wood touching soil. Keep pickets 2 inches off the ground or the bottoms rot in 3–5 years.
4. Forgetting the crown. Slightly crown concrete at each post base so water runs off, not in.
5. No expansion gaps on vinyl. Vinyl moves with temperature — follow the manufacturer's gap specs or panels buckle in summer.

Quick estimate formula

Pickets ≈ (length in feet × 12 ÷ 5.5), Posts ≈ (length ÷ 8) + 1

Example — 120-ft cedar privacy fence, DIY:

• Posts: 120 ÷ 8 + 1 = 16
• Pickets: 120 × 12 ÷ 5.5 = 262 (buy 275)
• Rails: 30, Concrete: 16 bags
• Materials: ~$2,200–$3,400

Want the full list done for you? Our free fence calculator builds your exact material count — posts, pickets, rails, and concrete — from just your fence length.