Shiplap Calculator
Transforming a room with shiplap is one of the most high-impact DIY projects you can tackle, but the “napkin math” can get complicated quickly.
Whether you are creating a stunning accent wall, a cozy mudroom, or wrapping an entire kitchen island, this tool removes the guesswork from your material run.
Use this calculator to determine exactly how many boards you need and get an instant estimate of your project cost before you head to the lumber yard.
How to Use This Shiplap Calculator
- Enter Wall Dimensions: Measure your wall’s Height and Width in feet. Round up to the nearest foot if you are unsure.
- Select Board Size: Choose your board width from the dropdown menu (e.g., standard 1×6 or 1×8).
- Note: If using a non-standard board, select “Custom Exposure” and enter the visible width of the board (excluding the tongue/overlap) in inches.
- Choose Board Length: Select the length of lumber available at your local store (commonly 8ft, 10ft, or 12ft).
- Subtract Exclusions: Enter the total square footage of any doors, windows, or fireplaces.
- Quick Reference: A standard door is roughly 21 sq. ft., and a standard double-hung window is roughly 12-15 sq. ft.
- Price & Waste:
- Enter the Price per Board to get a cost estimate.
- Adjust the Waste Factor slider. We default to 10% to account for cuts, mistakes, and defective boards.
- Click Calculate: Instantly see your total square footage, the specific number of boards to buy, and the estimated cost.
Important Notes & Disclaimers
- Estimates Only: This tool provides a mathematical estimate based on total surface area. It does not account for complex cuts around outlets, specific pattern matching (staggering joints), or non-rectangular walls.
- The “Tongue” Rule: When calculating custom widths, ensure you measure only the exposed face of the board. If you include the tongue/flange in your measurement, you will underestimate how many boards you need.
- Vertical vs. Horizontal: This calculator assumes a standard horizontal application. If installing vertically, your waste factor may need to be higher depending on your ceiling height relative to the board length.
💡 Pro Decor Tip: Before you start nailing, paint the drywall behind your shiplap the same color as the boards (or black). Wood naturally expands and contracts with the seasons; painting the wall ensures that if a slight gap opens up between boards, you won’t see raw white drywall peeking through!
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