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

Tread depth (cm)

Tread depth in centimeters.

Step count

Number of steps including the top landing step, at least two.

Compute the total stair run in centimeters as the tread depth times the number of steps minus one. 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]

Run length (cm)

Total horizontal run in centimeters, the tread depth times the step count minus one.

• 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.

• Tread Depth Check

  Check whether a stair tread depth falls in the ideal 28 to 29 cm range and report its deviation in centimeters.

• Tread Thickness Rule

  Recommend a stair tread thickness of 40 millimeters for string spans up to 90 centimeters and 50 millimeters beyond.

• Drawer Box Panel List Generator

  Compute the panel counts and total edge length for one drawer box from front width, box depth, and side height.