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

Run length (m)

Total railing run length in meters.

Maximum post spacing (m)

Maximum distance between neighboring posts in meters, between 0 and 3 exclusive, defaulting to 1.5.

Compute the number of railing posts needed for a run so the actual spacing never exceeds the maximum allowed post spacing. 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]

Posts required

Number of posts required, one more than the rounded-up spacing segments.

Actual spacing (m)

Actual uniform post spacing in meters, the run divided by the gaps between posts.

• 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.

• 4-Inch Baluster Spacing

  Count equal-width balusters and calculate equal clear gaps, including both end gaps, so none exceeds a four-inch maximum.

• Infill Gap Safety Check

  Check whether a railing infill gap keeps the 12 centimeter child-safety limit so a small head cannot pass through.

• Sockelfuss Anzahl

  Minimum number of plinth feet for two straight front and rear rows under a cabinet, using a chosen maximum spacing; excludes load-rating checks.