Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Includes a gap at each end. The maximum gap is a user input, not a statement of local safety rules.
Example Calculation
- Clear opening: 2000 mm
- Baluster width: 40 mm
- Maximum desired gap: 100 mm
A 2000 mm opening, 40 mm balusters and 100 mm maximum gap need 14 balusters; actual gap is 96 mm.
Frequently asked questions
How do I use this calculator?
Enter clear opening, baluster width, maximum desired gap. The result updates automatically. Use Reset to restore the example values.
What method does it use?
n=max(0,ceil((opening−maxgap)/(width+maxgap))); gap=(opening−n width)/(n+1).. Includes a gap at each end. The maximum gap is a user input, not a statement of local safety rules.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.