Shiplap Calculator

Shiplap has become a popular choice for creating accent walls and adding a touch of rustic or coastal charm to a room. Proper planning is key to a successful installation. Our Shiplap Calculator helps you determine exactly how many boards you'll need for your project, minimizing waste and ensuring you buy the right amount of material.

Understanding Shiplap Measurements

• Nominal Width: This is the stated width of the board (e.g., a 1x6 board).
• Actual Width: The true measured width of the board, which is usually less than the nominal width (e.g., a 1x6 is actually 5.5 inches wide).
• Reveal (or Exposure): The visible face of the board after it has been installed. Due to the overlapping "rabbet" joint, the reveal is less than the actual width. For example, a 5.5-inch wide shiplap board might have a 5-inch reveal.
• Waste Factor: An extra percentage of material (typically 10-15%) you should purchase to account for cuts, mistakes, and unusable board sections.

Practical Example

Let's calculate the shiplap needed for an accent wall with the following details:

• Wall Dimensions: 8 feet high by 12 feet wide (96" x 144")
• Shiplap Boards: 1x6 boards that are 8 feet long (actual width 5.5", reveal 5")
• Waste Factor: 10%

1. Wall Area: 96 inches × 144 inches = 13,824 square inches.
2. Coverage per Board: An 8-foot (96-inch) board with a 5-inch reveal covers 96" × 5" = 480 sq inches.
3. Number of Boards: 13,824 / 480 = 28.8 boards.
4. Total with Waste: roundup(28.8 × 1.10) = roundup(31.68) = 32 boards.

You would need to purchase 32 eight-foot shiplap boards for this wall.

Frequently Asked Questions (FAQ)

Why is the "reveal" different from the actual width?

Shiplap boards are designed with a special joint called a "rabbet," which allows them to overlap. This overlap hides the fasteners and creates the characteristic gap line. Because of this overlap, the visible face (reveal) is narrower than the board's full width.

What if my wall is longer than my boards?

If your wall is longer than your boards, you will need to create butt joints where two boards meet end-to-end. For a professional look, you should stagger these joints randomly across the wall so they don't all line up in one vertical line.

Should I install shiplap horizontally or vertically?

This is a design choice. Horizontal installation is more common and can make a room feel wider. Vertical installation can make a ceiling feel higher. The calculation method is the same for both orientations.