Stair Railing Calculator

Calculate stair railing materials β€” balusters, posts, and rails. Enter railing length and spacing requirements.

πŸͺœ Stair Railing Calculator

Results

Balusters37 pcs
Posts3 pcs
Top Rail12.00 lin ft
Bottom Rail12.00 lin ft

πŸ’‘ How to Calculate Stair Railing Materials

Building code requires railings on stairs with 4 or more risers. Rail height must be 34–38 inches measured from the stair nosing. Balusters must be spaced so a 4-inch sphere cannot pass through β€” typically 4 inches on center with standard balusters.

Posts are required at the top and bottom of each stair run, and every 6–8 feet along the run. Top and bottom rails run the full railing length. Calculate balusters by dividing the railing length by the on-center spacing, then add one.

A 12 ft stair railing at 4-inch baluster spacing: 37 balusters, 3 posts, 12 lin ft of top and bottom rail.

Stair Railing Calculator FAQ