CONSTRUCT MATH

Wood Fence Calculator — Pickets, Posts & Rails

Plan a wood privacy or picket fence. Counts pickets, posts, and rails for cedar, pressure-treated pine, or redwood at 4, 6, and 8-foot heights.

01

Enter Dimensions

ft
ft
in

Standard dog-ear picket: 3.5 in

in

Privacy fence: 0 in · Standard: 0.5 in

%
02

Results

Fence Posts

14posts

Rails

26rails

Pickets

330pickets

Sections

13sections

Each section = 8 ft wide

Editorial Standards

Each calculator is reviewed for formula accuracy, unit consistency, and alignment with current U.S. building practices before publication. We verify outputs against published engineering references and real-world project data. Learn more about our methodology.

A wood privacy fence is the most common backyard fence in the U.S. — cedar, redwood, or pressure-treated pine pickets on 4x4 posts set in concrete, with two or three horizontal 2x4 rails. This calculator estimates the post, rail, and picket count for any straight-run wood fence.

Pricing tip: pickets are usually the biggest line item by volume, but posts (especially pressure-treated 4x4×8 ft) often dominate the per-section cost once concrete is included.

How to Estimate a Wood Privacy Fence

4x4 posts 8 ft on-center · two or three 2x4 horizontal rails · butted cedar or redwood pickets.

Post count = ⌈Fence Length ÷ Spacing⌉ + 1 (for the end post). Rail count = 2–3 per fence section. Picket count = Fence Length ÷ picket width (with optional spacing gap).

Wood Fence Cost Drivers

  • Posts: 4x4×8 ft pressure-treated runs $15–$25 each in 2025. Cedar 4x4s $40–$60. Plan one bag of fast-set concrete per post hole minimum.
  • Rails: 2x4×8 ft pressure-treated ≈ $8–$12. Cedar 2x4×8 ft ≈ $14–$20.
  • Pickets: 5/8″ × 5-1/2″ × 6 ft cedar pickets run $4–$7 each. Dog-ear or French Gothic profiles cost slightly more.

Frequently Asked Questions

01

How many pickets do I need for a 100 ft wood fence?

For a 6 ft tall fence with standard 5-1/2 inch wide cedar pickets butted tight: 100 ft × 12 in/ft ÷ 5.5 in ≈ 219 pickets. Add 10% waste for cutoffs at posts and bad pickets — order 240.

02

What is the best wood for a privacy fence?

Western Red Cedar and Redwood are top choices — naturally rot- and insect-resistant, dimensionally stable, and weather to silver-gray. Pressure-treated pine is cheaper but warps more and needs annual staining. Cypress is regional but excellent in the Southeast.

03

How far apart should fence posts be?

8 ft on-center is standard for residential wood fences with 6 ft sections. 6 ft on-center is stronger for windy sites or 8 ft tall fences. Going wider than 8 ft causes top-rail sagging.

04

Do I need a top and bottom rail?

Yes — for any wood privacy fence taller than 4 ft, plan two horizontal rails (top and bottom). A third middle rail is required for fences over 6 ft tall to prevent picket cup-warping.

05

How long do wood privacy fences last?

Pressure-treated pine: 15–20 years; cedar: 20–30 years; redwood: 25–35 years. Lifespan drops significantly if posts are not set in concrete or if drainage is poor at the base.

Looking for the general calculator?

Calculate fence posts, rails, and pickets for any wood, vinyl, or chain-link fence. Enter total run length and spacing for an instant material takeoff.

Open the Fence Calculator: Posts, Rails & Pickets →

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