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

Opening between posts (mm)

Required number input.

Picket count

Required integer input.

Picket width (mm)

Required number input.

Calculate equal clear gaps between fence posts, pickets, and both ends from opening width and uniform picket width. 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]

Equal clear gap (mm)

The resulting equal clear gap 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.

• 4-Inch Baluster Spacing

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

• Sprossen Teilung Gleichmassig

  Equal clear opening width between identical muntins across a frame, including both end gaps.

• Trellis Lath Spacing

  Equal clear gap including both end gaps when equal-width trellis laths fill a known inside span.