Home / Ring size chart / Size 12½
Ring size 12½ in mm and international sizes
A US/Canadian size 12½ ring is 21.8 mm across the inside and 68.5 mm around. Larger sizes are stocked less often; check that a design is offered this large before falling for it.
- US / Canada
- 12½
- UK / Australia
- Z
- EU / ISO
- 68
- Japan / China
- 26
- India
- 28
- Italy / Spain / CH
- 28
- Inside diameter
- 21.8 mm
- Circumference
- 68.5 mm
- Diameter (in)
- 0.858″
Size 12½ and its neighbours
| US | UK | EU | Japan | Diameter | Circumference |
|---|---|---|---|---|---|
| 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 |
| 12¾ | Z | 69 | 27 | 21.99 mm | 69.1 mm |
| 13 | Z+1 | 70 | 27 | 22.20 mm | 69.7 mm |
Check it's really your size
A strip of paper wrapped around your finger should measure 67–70 mm for a size 12½. If you're buying a band 6 mm or wider, consider size 13 instead. Not sure? Try the ring size calculator or the online sizer.
Questions people ask
What is ring size 12½ in mm?
A US size 12½ ring has an inside diameter of 21.8 mm (0.858 in) and an inside circumference of 68.5 mm.
What is a US 12½ in UK and European sizes?
US 12½ is UK/Australian Z and EU (ISO) 68. In Italy, Spain and Switzerland it is 28.
What is a US 12½ in Japanese sizes?
The nearest Japanese and Chinese size is 26.
How do I know if I'm a size 12½?
Wrap a paper strip around your finger: if it measures about 68 mm, you're a 12½. Or measure a ring that fits: about 21.8 mm across the inside.