How to Calculate Stair Spindle Spacing (Guide & Calculator)
Everything you need to calculate the perfect spacing for your new stair balustrade.
Before you begin calculating, please ensure you have chosen your preferred style and size of spindle. Our standard spindle widths are 32mm, 35mm, 41mm, or 55mm.
There are two basic calculations used depending on whether you are fitting spindles to the Rake (the angled steps section of the stairs) or the Landing (the flat, horizontal section).
Interactive Spindle Calculator
Skip the math! Use our quick tools below to instantly calculate exactly how many spindles you need for your project.
Calculate Rake Spindles (The Steps)
Calculate Landing Spindles
Manual Calculation Formulas
If you prefer to check the math yourself, here is exactly how our calculator figures out the perfect spacing.
1. Spindle Spacing for the Rake (Steps)
To calculate the number of stair spindles required for the main staircase, simply count the number of treads (steps) on the rake section. Note: Do not include the landing area in this count.
The Rake Formula:
((Number of Steps) × 2) - 2 = Total Spindles Required
Why subtract two? You multiply by two because standard practice dictates two spindles per step. You then subtract two because you only require one spindle on the very top step and one on the very bottom step to make room for the newel posts.
Example: A balustrade you are looking to renovate has 13 steps.
(13 steps × 2) = 26.
26 - 2 = 24 spindles required for the rake.
2. Spindle Spacing for the Landing
If you also have a flat landing section, you will need to measure its total length in millimeters. Building regulations generally require gaps to be tight enough that a 100mm sphere cannot pass through, so our formula uses a safe 80mm gap.
Always round your final answer UP to the nearest whole number.
Example: A landing section you are renovating is 2200mm in length, and you are using a 41mm spindle.
Step 1: 2200mm - 80 = 2120
Step 2: 80 + 41mm = 121
Step 3: 2120 ÷ 121 = 17.52 Rounded up = 18 spindles required for the landing.
Need Help With Your Project?
Using the calculations above will result in perfect stair spindle spacing. However, if you are unsure or have an unusual staircase layout, please don't hesitate to contact our expert team!
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