Nickel Gap Calculator
Modern farmhouse shadowline calculation. Uses the true tongue-and-groove reveal formula (adding ⅛" reveal instead of subtracting lap overlap) for 100% precise board counts.
1. Wall Dimensions & Reveal Gap
Nickel Gap MathCalculated with ⅛" reveal added to visible course coverage.
Because Nickel Gap boards interlock with a face reveal rather than physically overlapping, each course covers slightly more area (5.50" vs 4.875" on 1×6), requiring ~10% fewer total boards.
Why Nickel Gap Math is Different from Traditional Shiplap
Many online calculators incorrectly apply overlapping rabbet formulas to nickel gap cladding. Here is why the geometry and board count calculations differ.
Overlapping Rabbet Joints
Standard shiplap has overlapping rabbeted edges. When board B rests on board A, 1/2 inch of wood is hidden inside the overlap.
Interlocking Reveal Gap
Nickel gap uses a tongue-and-groove shoulder. Boards do not overlap on the face; instead, they sit with an intentional 1/8" visible reveal.
Nickel Gap Installation & Reveal FAQs
What is the difference between shiplap and nickel gap? +
Traditional shiplap boards have overlapping rabbet edges that fit tightly together with little to no visible gap. Nickel gap boards feature a tongue-and-groove profile with a built-in 1/8-inch (the thickness of a standard US nickel coin) intentional gap or reveal that creates crisp, consistent horizontal shadow lines.
How is nickel gap calculated differently from standard shiplap? +
Standard shiplap subtracts the 0.5-inch overlap from actual board width (e.g. 5.375" minus 0.5" = 4.875" exposed face). Nickel gap adds the 0.125" reveal to the board face (e.g. 5.375" plus 0.125" = 5.50" effective course coverage). This makes nickel gap cover slightly more wall area per board.
Do you have to fill nail holes on nickel gap shiplap? +
No. If using tongue-and-groove nickel gap boards, you can drive 16-gauge finish nails at a 45-degree angle through the tongue shoulder. The next board's groove completely covers the nail, resulting in zero visible nail holes on the finished wall face.
What spacer should I use if installing DIY nickel gap with plywood strips? +
When creating DIY faux nickel gap by ripping 1/4-inch plywood underlayment, use actual US nickel coins or 1/8-inch tile spacers placed every 2 feet between boards as you nail them to the wall.
Thomas is a licensed finish carpenter and architectural woodworker with over 18 years of experience framing and installing interior millwork. Formulas audited against AWCI and standard NWFA milling standards.