Home / Ring size chart / Size 8
Ring size 8 in mm and international sizes
A US/Canadian size 8 ring is 18.1 mm across the inside and 57.0 mm around. This range covers many men's rings and larger women's sizes.
- US / Canada
- 8
- UK / Australia
- P½
- EU / ISO
- 57
- Japan / China
- 16
- India
- 17
- Italy / Spain / CH
- 17
- Inside diameter
- 18.1 mm
- Circumference
- 57.0 mm
- Diameter (in)
- 0.714″
Size 8 and its neighbours
| US | UK | EU | Japan | Diameter | Circumference |
|---|---|---|---|---|---|
| 7½ | O½ | 56 | 15 | 17.73 mm | 55.7 mm |
| 7¾ | P | 56 | 16 | 17.93 mm | 56.3 mm |
| 8 | P½ | 57 | 16 | 18.13 mm | 57.0 mm |
| 8¼ | Q | 58 | 16 | 18.34 mm | 57.6 mm |
| 8½ | Q½ | 58 | 17 | 18.54 mm | 58.2 mm |
Check it's really your size
A strip of paper wrapped around your finger should measure 56–58 mm for a size 8. If you're buying a band 6 mm or wider, consider size 8½ instead. Not sure? Try the ring size calculator or the online sizer.
Questions people ask
What is ring size 8 in mm?
A US size 8 ring has an inside diameter of 18.1 mm (0.714 in) and an inside circumference of 57.0 mm.
What is a US 8 in UK and European sizes?
US 8 is UK/Australian P½ and EU (ISO) 57. In Italy, Spain and Switzerland it is 17.
What is a US 8 in Japanese sizes?
The nearest Japanese and Chinese size is 16.
How do I know if I'm a size 8?
Wrap a paper strip around your finger: if it measures about 57 mm, you're a 8. Or measure a ring that fits: about 18.1 mm across the inside.