Baluster Calculator
Calculate the number of balusters (spindles) needed for your railing project with building code compliance
Calculate Railing Balusters
Total length of the railing section
Total number of posts in the railing
Width of each post
Width of each baluster (use widest part for irregular shapes)
Space between balusters (maximum 4"/99mm in most building codes)
Baluster Calculation Results
Maximum spacing: 4" (99mm) | Your spacing: 0.00"
Formula: Number of balusters = (Railing length - (Posts × Post width)) ÷ (Baluster width + Spacing)
Calculation: (0.0" - (0 × 0.0")) ÷ (0.0" + 0.0") = 0
Recommendation: Order 10-15% extra materials for waste and mistakes
Example Calculation
Deck Railing Example
Railing length: 20 feet (240 inches)
Number of posts: 5 posts
Post width: 2 inches each
Baluster width: 2 inches each
Baluster spacing: 3 inches
Step-by-Step Calculation
1. Available space = 240" - (5 × 2") = 240" - 10" = 230"
2. Baluster unit = 2" + 3" = 5"
3. Number of balusters = 230" ÷ 5" = 46 balusters
Result: 46 balusters needed
Building Code Guidelines
Maximum Spacing
4" (99mm)
Most building codes worldwide
Height Requirements
36" minimum
Residential railings
Load Requirements
200 lbs
Top rail load capacity
Common Baluster Types
Installation Tips
Always check local building codes before installation
Use the widest part for irregular baluster shapes
Order 10-15% extra materials for waste
Consider post caps and brackets in your design
Understanding Baluster Calculations
What are Balusters?
Balusters, also known as spindles, are the vertical supports between the top and bottom rails of a railing system. They provide safety and prevent people from falling while maintaining the aesthetic appeal of the railing.
Building Code Requirements
- •Maximum 4" (99mm) spacing between balusters
- •36" minimum railing height for residential
- •42" minimum for commercial applications
- •200 lbs minimum top rail load capacity
Calculation Formula
Balusters = (Length - Posts×Width) ÷ (Baluster + Spacing)
- Length: Total railing length
- Posts: Number of posts in the railing
- Width: Width of each post
- Baluster: Width of each baluster
- Spacing: Space between balusters
Important: Always round up to ensure adequate coverage and compliance
Wood Balusters
Traditional spindles, typically 1.5" to 2" wide, requiring precise spacing for safety compliance.
Metal Balusters
Sleek iron or aluminum balusters, often 0.5" to 1" wide, allowing for more balusters in the same space.
Cable Systems
Horizontal cables with 3" maximum spacing, providing modern aesthetics with unobstructed views.