Board-on-Board Fence Calculator

This tool helps you figure out exactly what you need for a board-on-board fence project:

• Total number of pickets required
• Number of fence panels or sections
• Accurate estimates based on your fence layout

Keep reading to learn how this style differs from standard fences, and how to calculate the materials like a pro.

What Makes Board-on-Board Fences Different?

Standard fences leave small gaps between pickets to allow airflow. But for full privacy, some builders close those gaps entirely. The issue? Wood naturally shrinks, creating new openings over time.

A board-on-board fence fixes that. It layers one picket over another, creating built-in coverage that hides gaps even after shrinkage. The result: true privacy, even long-term.

How to Calculate Pickets for a Board-on-Board Fence

You’ll need the following formula to calculate how many pickets to buy:

Number of Pickets = (Fence Length - Picket Width) ÷ (Picket Width - Overlap) + 1
  

Inputs required:

• Fence length
• Picket width
• Overlap amount

Tip: Always use the same units (inches, feet, etc.) and round up any decimal to the next whole number.

How Much Overlap Should You Use?

A simple rule:

Picket Overlap = 0.24 × Picket Width

That’s roughly 24% of the width to allow for potential shrinkage. This ensures no gaps appear later and gives a tight, finished look.

Examples:

• 3½" wide pickets → ~0.8" overlap
• 5½" wide pickets → ~1.3" overlap
• 11½" wide pickets → ~2.8" overlap

How Many Pickets Per 8-Foot Panel?

Here’s what you’ll need per 8-foot section, depending on your picket size and overlap:

• 5½" pickets with 1½" overlap → 24 pickets
• 3½" pickets with 1" overlap → 38 pickets

Use the calculator above to adjust based on your specific dimensions.

Related Tools to Check Out

• Concrete calculator for post holes
• Fence material estimator
• Wood fence calculator
• Picket calculator
• Full privacy fence calculator