Niche Tools Program

Deck baluster spacing calculator

Work out an exact, code-minded baluster layout for a deck, porch, or horizontal guard section. Enter the opening, baluster size, and maximum gap, then get the minimum baluster count, exact spacing, and mark list instantly in the browser.

Calculator

Results update instantly as you type. Use the button only if you want a shareable URL.

Units
End condition

What this solves

Baluster layouts usually fail in one of two ways: the gaps drift larger than expected, or the installer buys more balusters than needed because they are guessing at a safe count.

This calculator works backward from the maximum opening you want to allow. It picks the smallest baluster count that meets that limit, then gives exact left-edge and centerline marks for each piece.

This page is for horizontal sections only. Stair rake layouts need a different calculator because the measured opening changes on an angle.

Common use cases

  • Deck guard panels between two wood posts
  • Porch rail infill with square wood balusters
  • Shop-built railing panels where you want exact center marks before assembly