Baluster Calculator

Calculate balusters needed for deck or porch railings. Enter railing length, baluster width, and maximum gap spacing.

πŸͺ΅ Baluster Calculator

Results

Balusters Needed45 pcs
Actual Gap3.92 in
On-Center Spacing5.50 in

πŸ’‘ How to Calculate Balusters

Building code requires that a 4-inch sphere cannot pass through railing openings. This means the maximum gap between balusters is 3.5 inches (accounting for the sphere contacting both sides). Divide the railing length by on-center spacing (baluster width + gap), then add 1.

Standard balusters are 1.5 inches square (wood) or 0.75 inches (metal). Proper spacing ensures code compliance while maintaining visual balance. Use equal spacing β€” calculate the actual gap by distributing evenly across the full railing length.

A 20 ft railing with 1.5-inch wood balusters at 4-inch max gap: on-center spacing = 5.5 inches. Balusters = 44 pieces.

Baluster Calculator FAQ

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