Home / Ring size chart / Size 10½
Ring size 10½ in mm and international sizes
A US/Canadian size 10½ ring is 20.2 mm across the inside and 63.3 mm around. This range covers many men's rings and larger women's sizes.
- US / Canada
- 10½
- UK / Australia
- U½
- EU / ISO
- 63
- Japan / China
- 22
- India
- 23
- Italy / Spain / CH
- 23
- Inside diameter
- 20.2 mm
- Circumference
- 63.3 mm
- Diameter (in)
- 0.794″
Size 10½ and its neighbours
| US | UK | EU | Japan | Diameter | Circumference |
|---|---|---|---|---|---|
| 10 | T½ | 62 | 20 | 19.76 mm | 62.1 mm |
| 10¼ | U | 63 | 21 | 19.96 mm | 62.7 mm |
| 10½ | U½ | 63 | 22 | 20.16 mm | 63.3 mm |
| 10¾ | V | 64 | 23 | 20.37 mm | 64.0 mm |
| 11 | V½ | 65 | 23 | 20.57 mm | 64.6 mm |
Check it's really your size
A strip of paper wrapped around your finger should measure 62–65 mm for a size 10½. If you're buying a band 6 mm or wider, consider size 11 instead. Not sure? Try the ring size calculator or the online sizer.
Questions people ask
What is ring size 10½ in mm?
A US size 10½ ring has an inside diameter of 20.2 mm (0.794 in) and an inside circumference of 63.3 mm.
What is a US 10½ in UK and European sizes?
US 10½ is UK/Australian U½ and EU (ISO) 63. In Italy, Spain and Switzerland it is 23.
What is a US 10½ in Japanese sizes?
The nearest Japanese and Chinese size is 22.
How do I know if I'm a size 10½?
Wrap a paper strip around your finger: if it measures about 63 mm, you're a 10½. Or measure a ring that fits: about 20.2 mm across the inside.