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Ring size 12 in mm and international sizes
A US/Canadian size 12 ring is 21.4 mm across the inside and 67.2 mm around. Larger sizes are stocked less often; check that a design is offered this large before falling for it.
- US / Canada
- 12
- UK / Australia
- X½
- EU / ISO
- 67
- Japan / China
- 25
- India
- 27
- Italy / Spain / CH
- 27
- Inside diameter
- 21.4 mm
- Circumference
- 67.2 mm
- Diameter (in)
- 0.842″
Size 12 and its neighbours
| US | UK | EU | Japan | Diameter | Circumference |
|---|---|---|---|---|---|
| 11½ | W½ | 66 | 24 | 20.98 mm | 65.9 mm |
| 11¾ | X | 67 | 24 | 21.18 mm | 66.5 mm |
| 12 | X½ | 67 | 25 | 21.38 mm | 67.2 mm |
| 12¼ | Y½ | 68 | 25 | 21.59 mm | 67.8 mm |
| 12½ | Z | 68 | 26 | 21.79 mm | 68.5 mm |
Check it's really your size
A strip of paper wrapped around your finger should measure 66–68 mm for a size 12. If you're buying a band 6 mm or wider, consider size 12½ instead. Not sure? Try the ring size calculator or the online sizer.
Questions people ask
What is ring size 12 in mm?
A US size 12 ring has an inside diameter of 21.4 mm (0.842 in) and an inside circumference of 67.2 mm.
What is a US 12 in UK and European sizes?
US 12 is UK/Australian X½ and EU (ISO) 67. In Italy, Spain and Switzerland it is 27.
What is a US 12 in Japanese sizes?
The nearest Japanese and Chinese size is 25.
How do I know if I'm a size 12?
Wrap a paper strip around your finger: if it measures about 67 mm, you're a 12. Or measure a ring that fits: about 21.4 mm across the inside.