Baluster Calculator — Calculate Baluster Spacing & Count for Railings

Baluster Calculator

Calculate the perfect baluster spacing and count for your deck or staircase railing. Determine exactly how many balusters you need for any railing length.

Step 1: Railing Measurements

10 ft
1.5 in
4 in

Building Code Requirements

Most building codes require baluster spacing to be less than 4 inches to prevent small children from passing through. Always check local building codes for specific requirements.

Step 2: Calculation Options

Spacing Tips

For even spacing, calculate exact spacing first, then adjust if needed. Slight variations in spacing are often unnoticeable but must meet building code requirements.

Baluster Calculation Results

Summary
Visualization
Spacing Options

Total Balusters Needed

18
For a 10 ft railing with 4″ spacing
Actual Spacing
3.94 in
Total Spaces
19
Railing Coverage
42%
Code Compliance
✓ Compliant

Baluster Layout Visualization

Baluster Post Gap

Spacing Formula

Baluster Spacing Formula

Number of balusters = (Railing length – Total post width) ÷ (Baluster width + Desired spacing)
Actual spacing = (Railing length – Total post width – Total baluster width) ÷ (Number of balusters + 1)

Spacing Options Comparison

Spacing (inches) Balusters Needed Total Cost* Code Compliant

*Based on estimated $5 per baluster

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