Baluster Spacing Calculator
Even baluster spacing between posts: fewest balusters for the maximum gap you enter, exact gap and on-centre distance, layout marks, totals with waste.
Baluster count, clear gap, centre-to-centre spacing, the position of every baluster from the post, and totals over several sections with waste — the gap limit is yours.
Example: A 60 in opening with 1½ in balusters and a 4 in maximum gap needs 11 balusters: gaps of 3.625 in, 5.125 in on centre, the first centre 4.375 in from the post; 35 for three sections with 5 % waste.
Even gaps,
from the fewest balusters.
The spacing arithmetic, the layout marks, and where the gap limit comes from.
The arithmetic
n balusters make n + 1 gaps: gap = (opening − n × width) ÷ (n + 1). For a maximum gap g the fewest balusters is n = ⌈(opening − g) ÷ (width + g)⌉; or enter a count and read the gap. Centre-to-centre spacing is gap + width; the first centre sits gap + width/2 from the post, and every mark is listed.
The gap limit
The maximum clear gap is the one you enter. Railing codes state a limit (often expressed as a sphere that must not pass); which limit applies to your railing is a local matter, so the page does not embed one.
Totals
Several identical sections multiply the count; waste is added as a percentage and rounded up. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- Even-spacing arithmetic: n balusters make n + 1 equal gaps; the maximum gap is a user input (railing codes state the limit; none embedded)
Last reviewed 20 September 2026. How results are checked: How we verify.