Railing Post Spacing
Count railing posts and check the actual spacing.
About Railing Post Spacing
Posts must sit within a maximum spacing, so dividing the railing length by that limit and adding one gives the minimum post count. Rail posts are load-critical and spacing limits are code-mandated, so verifying count against the length avoids weak sections.
Formula
Railing Post Spacing
Posts = railing length / max spacing + 1
- max spacing
- Code limit between rail posts
Worked example
With the default values below, Railing Post Spacing returns Posts per Side of 5. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Railing length
- 20 ft
- Max post spacingminimum 1 ft
- 6 ft
- Number of sidesminimum 1
- 1
Results
- Posts per Side
- 5
- Actual Spacing
- 5.00 ft
- Total Posts
- 5
Step by step
- 1Values used
- 2Railing Post Spacing
- 3Posts per Side= 5
- 4Actual Spacing= 5.00 ft
- 5Total Posts= 5
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Railing Post Spacing calculated?
Posts = railing length / max spacing + 1 Posts must sit within a maximum spacing, so dividing the railing length by that limit and adding one gives the minimum post count.
Why does Railing Post Spacing matter?
Rail posts are load-critical and spacing limits are code-mandated, so verifying count against the length avoids weak sections.
What values do I need to enter?
This calculator takes 3 inputs: Railing length, Max post spacing, Number of sides. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.