Baluster Measuring and Spacing Diagram

This quick and easy guide will show the basics in baluster spacing on both level balcony surface and on your stair treads / steps. Keep in mind that the standard building code requirement is that you can not have a gap greater than 4 inches in any part of your stair and railing system.

Tools Required

  • Measuring Tape & Pen

How to Measure the Balcony – Balcony and Level (flat) surface is the most easy place to measure. Simply measure from wall to wall or newel post to newel post (or newel post to wall). Multiply this measurement by 3 and this will give you the total number of balusters you can expect. Example, 20 feet of balcony would require 60 balusters. 20 x 3 = 60 Total Feet x 3 = Total Balusters

How to Measure Steps – Calculate the amount of balusters you need on each step by counting the number of steps and multiplying by 3. You need 3 baluster per step. (Note: some steep staircases might use 2 per step, and sometimes 2 one one step and 3 on the next. It all depends on making sure you don’t have any gaps greater than 4 inches!) Also don’t forget some staircases are open on both sides, so you need balusters for both sides of the step!

General Baluster Spacing – The general rule of thumb is to have 3 baluster per foot so you do not have any gaps greater than four inches. If you put one baluster every 4 inches on center, then you will typically always be fine. See diagram below.

Now a few things to consider when trying to space your baluster.

  • You have an uneven measurement. If this happens, cheat the design over until you can have an even space on both ends of the run .So you might not have a 4 inch gap on both ends, you might only have 3 inch for example.
  • Your stair treads are small or has a larger overhand than normal. In this case you need to evenly space out the baluster on each tread. Find the center of your usable tread space, work your way out until you can fit the balusters on that tread without going over or hitting the tread on the upper step. Play around and see what works.

Baluster Measuring and Spacing Diagram