Material List Overview
Building a wood fence requires careful material planning to avoid multiple trips to the lumber yard and ensure a consistent look across the entire fence. The primary materials for a standard privacy fence include pressure-treated 4x4 posts, 2x4 horizontal rails, 1x6 (or 1x4) pickets, fast-setting concrete for post footings, and exterior-grade screws or nails. Secondary materials include post caps, gravel for drainage at the bottom of post holes, and optional stain or sealant.
This calculator provides exact quantities based on your fence dimensions and specifications. It accounts for standard lumber lengths (8-foot rails, posts cut to appropriate length) and includes a reasonable allowance for waste and damaged boards. Always purchase 5-10% extra pickets to account for defective boards, cutting waste, and future repairs.
Material Calculation Formulas
The gap between pickets is typically 0 inches for a privacy fence (boards butted together) or 1.5-2 inches for a spaced picket fence. This calculator assumes a privacy fence with 0.25-inch spacing to allow for wood expansion. Each post hole requires concrete -- the amount depends on fence height and post size.
Lumber Sizes Reference
| Component | Nominal Size | Actual Size | Common Length | Material |
|---|---|---|---|---|
| Line Posts | 4x4 | 3.5" x 3.5" | 8 ft / 10 ft | Pressure-treated #2 |
| Corner/Gate Posts | 6x6 | 5.5" x 5.5" | 8 ft / 10 ft | Pressure-treated #2 |
| Rails | 2x4 | 1.5" x 3.5" | 8 ft | Pressure-treated #2 |
| Pickets | 1x6 | 0.75" x 5.5" | 6 ft / 8 ft | Pressure-treated / cedar |
| Pickets (narrow) | 1x4 | 0.75" x 3.5" | 4 ft / 6 ft | Pressure-treated / cedar |
Hardware & Fasteners
The right fasteners are essential for a long-lasting fence. Use hot-dipped galvanized or stainless steel screws with pressure-treated lumber to prevent corrosion. For attaching pickets to rails, use #8 x 2-inch exterior screws (2 per picket per rail). For attaching rails to posts, use 3-inch structural screws, rail brackets, or galvanized nails. Estimate approximately 1 pound of screws per 5 linear feet of fence for a 6-foot privacy fence with 3 rails.
Worked Example
A 150-foot privacy fence, 6 ft tall, 8 ft post spacing, 1x6 pickets, 3 rails:
Posts = 19 + 1 = 20 posts (4x4 x 9 ft)
Rails = 19 × 3 = 57 rails (2x4 x 8 ft)
Pickets = (150 × 12) ÷ (5.5 + 0.25) = 313 pickets (1x6 x 6 ft)
Concrete = 20 × 2 = 40 bags (50 lb fast-setting)
Screws = 313 × 3 rails × 2 = 1,878 screws ≈ 6 lbs
Frequently Asked Questions
Should I use nails or screws for a fence?
Screws provide superior holding power and are easier to remove for repairs, but they cost more and take longer to install. Ring-shank nails are a good compromise -- they provide better holding power than smooth nails and are faster to install with a nail gun. For pickets, either 2-inch screws or 8d ring-shank nails work well. For structural connections (rails to posts), always use screws or lag bolts.
How much extra material should I buy?
Purchase 10% extra pickets to account for warped, split, or damaged boards and cutting waste. For posts and rails, buy 1-2 extra of each. It is easier and cheaper to return unused materials than to make an additional trip to the store and risk a different lot of lumber that may not match.
What size post do I need for a 6-foot fence?
For a standard 6-foot privacy fence, use 4x4 posts that are 8 or 9 feet long (allowing 24-36 inches below ground). For corner posts, end posts, and gate posts, upgrade to 6x6 for added strength. In high-wind areas or for fences over 6 feet, use 6x6 posts throughout.
Do I need pressure-treated lumber?
All ground-contact components (posts) must be pressure-treated to resist rot and insect damage. Rails should also be pressure-treated since they are close to the ground and exposed to moisture. Pickets can be pressure-treated, cedar, or redwood -- cedar and redwood are naturally rot-resistant and can be left to weather to a silver-gray patina or stained.