# Fence Picket Calculator

Calculate fence pickets, posts, and rails needed for your project. Enter fence length, picket size, and spacing. Includes waste factor. Free fence calculator.

## What this calculates

Buying the right number of pickets saves you a trip back to the lumber yard (and the temptation to skip the last 10 feet). Enter your fence dimensions, picket size, and gap preference, and this calculator gives you exact picket, post, and rail counts with a waste factor built in.

## Inputs

- **Total Fence Length** (ft) — min 0
- **Fence Height** (ft) — min 3, max 8 — Common heights: 4 ft (front yard), 6 ft (privacy)
- **Picket Width** (in) — min 1, max 8 — Standard 1x4 picket = 3.5 in, 1x6 = 5.5 in
- **Gap Between Pickets** (in) — min 0, max 4 — 0 for privacy fence, 1.75 for shadowbox, 2-3 for picket
- **Post Spacing** (ft) — min 4, max 10 — Standard post spacing: 6-8 ft on center
- **Rails Per Section** — min 1, max 4 — 2 rails for fences under 5 ft, 3 for 6 ft+
- **Waste Factor** (%) — min 0, max 25 — Extra material for cuts and defects (10% typical)

## Outputs

- **Pickets Needed** — Includes waste factor
- **Posts Needed**
- **Rails Needed** — Horizontal 2x4 rails
- **Fence Sections**
- **Post Length** (ft) — Fence height + burial depth

## Details

The picket count formula divides the total fence length (in inches) by the combined width of one picket plus one gap. For a privacy fence with zero gap and 3.5-inch pickets, that works out to about 3.43 pickets per linear foot, or roughly 27 pickets per 8-foot section.

Posts are spaced every 6 to 8 feet on center. Eight-foot spacing is the most common because standard lumber comes in 8-foot lengths, so your 2x4 rails fit perfectly between posts without cutting. If you are building in a windy area or using heavier pickets, drop to 6-foot spacing for extra strength.

The waste factor accounts for knots, splits, warped boards, and cutting errors. A 10% waste factor is standard for fence projects. If you are using pre-stained or premium pickets that come in consistent quality, you can drop to 5%. For rough-sawn cedar with more natural variation, go with 15%.

## Frequently Asked Questions

**Q: How many pickets do I need per foot of fence?**

A: With standard 3.5-inch pickets and no gap (privacy fence), you need about 3.43 pickets per linear foot. With a 2-inch gap (traditional picket fence), you need about 2.18 per foot. Multiply by your total fence length and add 10% for waste.

**Q: What size lumber do I need for fence rails?**

A: Most fence rails use 2x4 lumber. For an 8-foot section, you need 8-foot 2x4s. Some builders prefer 2x3 rails for lighter fences or use 16-foot 2x4s to span two sections and reduce the number of joints. Always use pressure-treated wood for outdoor fencing.

**Q: Should I use 1x4 or 1x6 pickets?**

A: 1x4 pickets (3.5 inches wide) are the most common for traditional fences. 1x6 pickets (5.5 inches wide) cover more area with fewer boards, which means faster installation and fewer gaps to worry about. Dog-ear 1x6 cedar is the most popular choice for privacy fences.

**Q: How deep should fence posts be buried?**

A: Bury at least one-third of the post length, with a minimum of 2 feet. For a 6-foot fence, use 8-foot posts with 2 feet in the ground. In cold climates, set posts below the frost line to prevent heaving. Always set posts in concrete for stability.

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Source: https://vastcalc.com/calculators/construction/fence-picket
Category: Construction
Last updated: 2026-04-08