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

Going Millimeters (mm)

Required number input.

Riser Millimeters (mm)

Required number input.

Compute the German stair safety-rule dimension as tread going plus riser height; this is a planning metric, not a structural or code 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]

Safety Millimeters (mm)

The resulting safety 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.

• Treppen Bequemlichkeitsregel

  Compute the German stair comfort-rule dimension as tread going minus riser height; interpret it as a planning metric, not proof of code compliance.

• Treppen Schrittmassregel

  Blondel stair stride dimension 2×riser plus tread going, a planning check rather than a code-compliance determination.

• Riser Height Check

  Check whether a stair riser height falls in the ideal 17 to 18 cm range and report its deviation in centimeters.