Switzerland · 28 sizes

Swiss Ring Size Chart.

Numeric scale used by Swiss makers, roughly 0 to 27.

Every row is computed from inner circumference, so the diameter and the equivalents in other systems are consistent all the way down.

Swiss	Diameter	Circumference	Indian	US / Canada	EU / ISO 8653	UK / Australia	Japan / China
0	12.73 mm	40.0 mm	—	—	—	C½	—
1	13.05 mm	41.0 mm	—	—	—	D	1
2	13.37 mm	42.0 mm	1	—	—	E	2
3	13.69 mm	43.0 mm	2	—	—	E½	3
4	14.01 mm	44.0 mm	3	3	44	F½	4
5	14.32 mm	45.0 mm	5	3½	45	G	6
6	14.64 mm	46.0 mm	6	3½	46	H	7
7	14.96 mm	47.0 mm	7	4	47	H½	8
8	15.28 mm	48.0 mm	8	4½	48	I½	9
9	15.60 mm	49.0 mm	9	5	49	J½	10
10	15.92 mm	50.0 mm	10	5½	50	K	11
11	16.23 mm	51.0 mm	11	5½	51	L	12
12	16.55 mm	52.0 mm	13	6	52	L½	13
13	16.87 mm	53.0 mm	14	6½	53	M½	14
14	17.19 mm	54.0 mm	15	7	54	N	15
15	17.51 mm	55.0 mm	16	7½	55	O	16
16	17.83 mm	56.0 mm	17	7½	56	P	18
17	18.14 mm	57.0 mm	18	8	57	P½	19
18	18.46 mm	58.0 mm	19	8½	58	Q½	20
19	18.78 mm	59.0 mm	20	9	59	R	21
20	19.10 mm	60.0 mm	22	9	60	S	22
21	19.42 mm	61.0 mm	23	9½	61	S½	23
22	19.74 mm	62.0 mm	24	10	62	T½	24
23	20.05 mm	63.0 mm	25	10½	63	U½	25
24	20.37 mm	64.0 mm	26	11	64	V	26
25	20.69 mm	65.0 mm	27	11	65	W	27
26	21.01 mm	66.0 mm	28	11½	66	W½	—
27	21.33 mm	67.0 mm	29	12	67	X½	—

Convert Swiss to another system

A jeweller's own chart takes precedence over this one — makers differ by a fraction of a size and a proper mandrel beats a paper strip. Fingers also swell through the day and in heat, so measure in the evening. How to measure at home →