Fence Calculator

What this calculator does

This calculator estimates the materials needed to build a fence: the number of posts, rails, pickets or panels, concrete for post holes, and total linear footage. It helps homeowners and contractors plan material purchases and budget for a fencing project.

Building a fence is one of the most common and impactful home improvement projects—it adds privacy, security, curb appeal, and property value. But material estimation can be tricky because you need to coordinate posts, rails, and infill (pickets or panels) with specific spacing rules. Under-ordering means a second trip to the lumber yard; over-ordering wastes money on materials that are difficult to return.

This tool supports common fence styles including privacy (board-on-board), picket, ranch/split rail, and panel fences, with customizable dimensions and spacing.

How to use it

1. Enter the total fence length in linear feet.
2. Enter the fence height (e.g. 6 ft for privacy, 4 ft for picket).
3. Select the fence style (privacy, picket, panel, or rail).
4. Enter the post spacing (typically 6 or 8 feet on center).
5. Review the number of posts, rails, pickets/panels, and concrete bags needed.

Formulas used

• Number of posts = (Total length / Post spacing) + 1 Add extra posts for corners and gates. Example: 150 ft fence / 8 ft spacing + 1 = 20 posts.

• Number of rails = (Number of sections) × Rails per section Typically 2 rails for fences under 5 ft, 3 rails for 6 ft+ fences. Example: 19 sections × 3 rails = 57 rails (8 ft lengths).

• Pickets = Total length / (Picket width + Gap) Example: 150 ft (1,800 in) / (3.5" picket + 0" gap for privacy) = 514 pickets.

• Panels = Number of sections = Posts − 1 Example: 20 posts → 19 panels (for pre-built panel fences).

• Concrete per post = 1–2 bags of 50 lb quick-set per post (for 2 ft deep holes, 8–10" diameter). Example: 20 posts × 2 bags = 40 bags.

Examples

Example 1 — 6 ft privacy fence, 150 linear ft: Post spacing = 8 ft. Posts = 20 (4×4×8 ft). Rails = 57 (2×4×8 ft). Pickets = 514 (1×6×6 ft). Concrete = 40 bags.

Example 2 — 4 ft picket fence, 80 linear ft: Post spacing = 8 ft. Posts = 11. Rails = 20 (2 per section). Pickets = 192 (3.5" wide, 1.5" gap). Concrete = 22 bags.

Example 3 — Pre-built panel fence, 200 linear ft: Post spacing = 8 ft (matching panel width). Posts = 26. Panels = 25 (6 ft × 8 ft pre-assembled). Rails = included in panels. Concrete = 52 bags.

Tips and common mistakes

• Check your property line. Before building, confirm your boundary with a survey. Most jurisdictions require the fence to be set inside your property line (typically 2–6 inches). Building on or over the line can result in a forced removal.
• Check local codes and HOA rules. Many areas restrict fence height (4 ft front yard, 6 ft backyard is common) and require permits for fences over a certain height.
• Add 10% for waste. Lumber can be warped, split, or cut wrong. Order a few extra pickets, a couple extra rails, and one extra post.
• Account for gates. Each gate needs its own posts (often 4×4 or 4×6 for heavy gates), hinges, and a latch. Subtract the gate width from total fence length when calculating pickets/panels.
• Set posts in concrete below the frost line. In cold climates, post holes should be 36–48 inches deep to prevent frost heave. In mild climates, 24 inches is typical.
• Use pressure-treated or cedar lumber for ground contact and weather resistance. Untreated pine will rot within a few years.