Ring size conversion chart

Convert Japanese 号, US, UK, and EU (ISO) ring sizes. Every row links to a dedicated page with diameter, circumference, and neighboring sizes.

Published July 11, 2026

Full conversion table

Ø mm	Circ. mm	Japan	US	UK	EU
14	44	4	3	F	44
14.4	45.2	5	3.5	G	45
14.8	46.5	6	4	H	46
15.2	47.8	7	4.5	I	48
15.6	49	8	5	J½	49
16	50.3	9	5.5	K½	50
16.4	51.5	10	6	L½	51
16.8	52.8	11	6.5	M½	53
17.2	54	12	7	N½	54
17.6	55.3	13	7.5	O½	55
18	56.6	14	8	P½	57
18.4	57.8	15	8.5	Q½	58
18.8	59.1	16	9	R½	59
19.2	60.3	17	9.5	S½	60
19.6	61.6	18	10	T½	62
20	62.8	19	10.5	U½	63
20.4	64.1	20	11	V½	64
20.8	65.3	21	11.5	W½	65
21.2	66.6	22	12	X½	67
21.6	67.9	23	12.5	Z	68
22	69.1	24	13	Z+1	69
22.4	70.4	25	13.5	Z+2	70
22.8	71.6	26	14	Z+3	72
23.2	72.9	27	14.5	Z+4	73

Example: US 7 = US 7 = UK N½ = EU 54 = Japan 12.

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