Enter your Total Railing Length, Spindle Width, Maximum Gap Between Spindles, Space from Post to First Spindle, and Installation Type to calculate exactly how many spindles you need — plus the Actual Spacing, Center-to-Center Distance, and Total Spindle Width so your railing looks even and meets code without any guesswork.
Total Spindles Needed
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Actual Spacing Between Spindles
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Center-to-Center Distance
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Total Width of All Spindles
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Building codes typically require that gaps between spindles be no more than 4 inches to prevent children from getting their heads stuck. Always check your local building codes as requirements may vary by location.
The number of spindles depends on your railing length, spindle width, and required spacing. Use our calculator to determine the exact number needed for your specific project dimensions.
Divide the available space (total length minus spindle widths) by the number of gaps needed. Our calculator automatically determines the optimal spacing to ensure even distribution while meeting code requirements.
For slanted stair railings, you'll need to measure the horizontal distance along the stair treads, not the angled length of the railing itself. Use this horizontal measurement in the calculator.
Yes, horizontal spindles are allowed in many areas, but the same 4-inch maximum spacing rule typically applies. Horizontal railings may have different code requirements, so check with local authorities.
Posts are vertical supports that connect to the deck structure. Spindles (also called balusters) are the smaller vertical pieces between posts that provide the safety barrier.
For curved railings, measure the arc length and use that as your total length. You may need to adjust spindle angles slightly to follow the curve properly.