Use this workshop calculation to turn measured dimensions and the selected construction convention into a cut, spacing, fit, or material-planning value.

Face Board Millimeters (mm)

Required number input.

Penetration Millimeters (mm)

Required number input.

Minimum nail length from the thickness of the attached board and a separately chosen penetration depth into the receiving member; not a withdrawal-capacity check. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Minimum Nail Millimeters (mm)

The resulting minimum nail millimeters returned as a number.

• Nominal dimensions, kerf, moisture movement, hardware clearances, wall squareness, and manufacturer instructions can change the required shop dimension. Measure the actual assembly and test critical joints on scrap before cutting finished material.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Complement the calculated dimension with a physical story stick, dry fit, or full-size layout. Follow the hardware, coating, adhesive, or machine manufacturer's limits where they differ from a rule of thumb.

• Screw Length Rule

  Minimum screw length to pass through the first member and reach a specified embedment in the receiving member; excludes countersinking.

• Dado Depth

  Calculate target dado depth from board thickness and an explicitly chosen fraction of that thickness.

• Nail Withdrawal Estimate

  Estimate nail withdrawal resistance in kilograms from shank diameter, penetration depth, and wood group.