Size Studio
Ring Size 11.5 in UK, EU and Inside Diameter (mm)
A US (and Canadian) ring size 11.5 is a UK W½ and an EU 66, with an inside diameter of about 21 mm (65.8 mm around).
| US / CA | UK / AU | EU (ISO) | Japan | Inside diameter | Inside circumference |
|---|---|---|---|---|---|
| 11.5 | W½ | 66 | 25 | 21 mm | 65.8 mm |
Good to know
- EU (ISO) ring sizes are the inside circumference in millimetres. US sizes go up about 0.8 mm in diameter per whole size, UK letters about 0.4 mm.
- Fingers swell when warm. Measure at the end of the day, and go half a size up for wide bands.
Sizes either side
Smaller: 11Larger: 12Open the full converterHow to measure yourself
Questions
What is ring size 11.5 in mm?
About 21 mm inside diameter, 65.8 mm around.
What is ring size 11.5 in UK?
UK W½.
What is ring size 11.5 in EU?
EU 66.
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