Italian/Swiss ring size to US size
Italian gold is common in Gulf shops, and its size is a small number like 12 or 14.
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How to use it
- Enter italian/swiss size.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Circumference (mm) = Italian size + 40, then US = (C ÷ (π × 25.4) − 0.458) ÷ 0.032 and EU = C.
Example
Inputs: Italian/Swiss size = 14. Result: US size: 6.75; UK size: N; EU size (ISO): 54.
Limits and caveats
- Sizes are rounded to the nearest step of each system, and shop mandrels can differ slightly.
- Some Italian makers use older charts that differ by one size, so ask for the circumference in mm.
Questions about this tool
What is Italian size 14?
It is 54 mm around, about US 6.75 and UK N.
Is the Swiss size the same as Italian?
Yes, Switzerland, Italy and Spain write the circumference minus 40.
How do I get the EU size?
Add 40, so Italian 12 is EU 52.