Home & Construction

Fence Calculator — Free 2026

Calculate posts, rails, pickets and boards needed for your fence project. Enter your dimensions and get an instant materials list.

Total Fence Length (ft)

Fence Height (ft)

Post Spacing (ft)

Gate Width (ft)

Number of Gates

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Posts Needed

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Rails Needed

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Pickets / Boards

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Fence Length (ft)

How It Works

Enter fence dimensions
Add gates
Read your results

How to Estimate Fence Materials

Building a fence is one of the most common home improvement projects, and accurate material estimation is essential to staying on budget. The three main components — posts, rails, and pickets or boards — are all calculated from the total fence length, height, and post spacing. This calculator handles the math including gate openings and appropriate rail counts based on fence height.

Posts and Spacing

Posts are the backbone of any fence. Standard spacing is 8 feet on center for privacy fences, which balances material cost with structural integrity. In high-wind areas or for taller fences, reduce spacing to 6 feet. Each gate requires two dedicated gate posts, which are typically larger than line posts (6x6 vs 4x4) to support the gate hardware. For concrete footings at each post location, use our concrete calculator to estimate the amount needed.

Rails and Pickets

Rails run horizontally between posts and support the vertical pickets. Fences under 5 feet need 2 rails, while 6-foot and taller fences require 3 rails for stability. Pickets for a standard privacy fence are 5.5 inches wide with no gap between them, requiring roughly 2.18 pickets per linear foot. This calculator accounts for gate openings by subtracting gate widths from the fenced length. For measuring your property lines accurately, our square footage calculator can help determine the total area.

Ordering Tips

Always order 10-15% extra materials to account for defective boards, cutting waste, and future repairs. Pressure-treated pine is the most economical choice, while cedar and redwood offer natural rot resistance at a premium price. When ordering, verify that post lengths account for burial depth — a 6-foot fence needs 8-foot posts to allow for 2 feet of in-ground depth plus concrete footer.

Frequently Asked Questions

How do I calculate how many fence posts I need?

Divide the total fence length by the post spacing distance, then add 1 for the end post. For example, a 100-foot fence with 8-foot spacing needs 14 posts. Add extra posts for corners and gate openings — each gate needs 2 gate posts.

How many rails do I need for a fence?

Fences up to 5 feet typically use 2 rails (top and bottom). Fences 6 feet and taller should have 3 rails. Multiply the number of fence sections by the number of rails per section.

How far apart should fence posts be?

Standard post spacing for wood privacy fences is 8 feet center to center. For picket fences or high-wind areas, reduce spacing to 6 feet. Post holes should be dug to one-third the total post length.

How many pickets do I need for a privacy fence?

For a standard privacy fence with 5.5-inch wide pickets and no gap, divide the total fence length in inches by 5.5 and round up. A 100-foot fence needs about 218 pickets. Always add 10% extra for waste and cutting.