If you’re replacing balusters, send measurements or an old part. For new builds, we’ll help you match the correct height and bottom width for your stair system.

Understanding Baluster Size and Proportions

Choosing the right baluster size for your home is about both fit and visual balance in the space. Balusters (also called spindles) must match the proportions of your staircase, railing height, and tread spacing to look correct and meet building codes.

The vast majority of interior stair balusters measure somewhere between 34 and 42 inches in height, depending on your overall rail height. The bottom width (or square base) typically ranges from 1 ¼” to 1 ¾” for standard stair systems. However, custom or larger-scale designs may require wider bases for a more substantial appearance.

If you’re replacing existing stair parts, we can match your current dimensions or help you choose the closest equivalent.

Key Factors to Determine Correct Baluster Size

  • Handrail Height: Measure from the tread nosing to the bottom of the handrail. Most U.S. stair codes require a total rail height of 34”–38” for interior stairs, which will dictate your baluster height.
  • Stair Pitch and Step Count: The steeper or longer your stair run, the more spacing precision you’ll need for a uniform visual line. Our team can help calculate spacing and height to keep every spindle aligned properly.
  • Baluster Width (Base or Square): Wider bases provide a stronger look for open or grand staircases. Thinner profiles are better for modern designs. For porch and other exterior applications, slightly larger profiles are often used for stability and proportion.
  • Building Code Compliance: For safety, most local codes require about 4 inches or fewer of spacing between balusters. This ensures a child’s head or small object can’t pass through the gap.

If you need help calculating how many balusters you need for a railing or stair run to meet common spacing guidelines, click here to try our Baluster Spacing Calculator.

Matching Style to Function

While size determines proportion and safety, the style of your baluster defines the visual representation of your staircase. Traditional turned profiles are great for detailed interiors. Smooth or square designs fit modern homes.

Arnold Wood Turning can customize dimensions, turning style, and species to perfectly complement your home’s aesthetic and meet the structural requirements of your staircase.

Replacements vs. New Installations

If you’re replacing existing wood balusters, simply send us a measurement or a sample piece. We’ll match the dimensions and profile! For new builds, we can recommend a size range and spacing layout.

We can also assist homeowners and contractors with design drawings or spacing calculations to ensure code compliance and visual consistency across the staircase.

If you’re unsure what size balusters your project requires, send a quick photo or measurement to our team. We’ll help you determine the right height, width, and spacing for your staircase. We can also quote your custom wood baluster project or complete spindle sets for free, made to order in your preferred species.