ISO 57 in US Ring Size

ISO 57 ≈ US 8

Ring Size

Inner circumference:56.4-57.7mm

Ring Sizes Around ISO 57

US	UK	ISO / EU	JP / KR	Diameter (mm)	Circumference (mm)
6.5	M	53	13	16.9	53.1
7	N	54	14	17.3	54.4
7.5	O	56	15	17.7	55.7
8	P	57	16	18.1	57
8.5	Q	58	18	18.6	58.3
9	R	60	19	18.9	59.5
9.5	S	61	20	19.4	60.8

Nearby sizes:

Does ISO 57 round up or down in US?

Between 8 and 8.5, remember a finger can gain close to a full size from a cool morning to a hot afternoon, so round to the warm-hand measurement.