Home / Ring size chart / Size 5½
Ring size 5½ in mm and international sizes
A US/Canadian size 5½ ring is 16.1 mm across the inside and 50.6 mm around. This sits in the most commonly sold range for women's rings, according to jeweler sizing guides.
- US / Canada
- 5½
- UK / Australia
- K½
- EU / ISO
- 51
- Japan / China
- 10
- India
- 11
- Italy / Spain / CH
- 11
- Inside diameter
- 16.1 mm
- Circumference
- 50.6 mm
- Diameter (in)
- 0.634″
Size 5½ and its neighbours
| US | UK | EU | Japan | Diameter | Circumference |
|---|---|---|---|---|---|
| 5 | J½ | 49 | 9 | 15.69 mm | 49.3 mm |
| 5¼ | K | 50 | 10 | 15.90 mm | 49.9 mm |
| 5½ | K½ | 51 | 10 | 16.10 mm | 50.6 mm |
| 5¾ | L | 51 | 10 | 16.30 mm | 51.2 mm |
| 6 | L½ | 52 | 11 | 16.51 mm | 51.9 mm |
Check it's really your size
A strip of paper wrapped around your finger should measure 49–52 mm for a size 5½. If you're buying a band 6 mm or wider, consider size 6 instead. Not sure? Try the ring size calculator or the online sizer.
Questions people ask
What is ring size 5½ in mm?
A US size 5½ ring has an inside diameter of 16.1 mm (0.634 in) and an inside circumference of 50.6 mm.
What is a US 5½ in UK and European sizes?
US 5½ is UK/Australian K½ and EU (ISO) 51. In Italy, Spain and Switzerland it is 11.
What is a US 5½ in Japanese sizes?
The nearest Japanese and Chinese size is 10.
How do I know if I'm a size 5½?
Wrap a paper strip around your finger: if it measures about 51 mm, you're a 5½. Or measure a ring that fits: about 16.1 mm across the inside.