Conversion · Japan to Switzerland

Japan / China to Swiss ring sizes.

Japan / China 14 = Swiss 13 16.79 mm across · 52.7 mm around

Both scales describe the same physical ring. The table below converts every size in the range, derived from inner circumference rather than copied.

Japan / China	Swiss	Diameter	Circumference
1	1	12.99 mm	40.8 mm
2	2	13.28 mm	41.7 mm
3	3	13.58 mm	42.7 mm
4	4	13.87 mm	43.6 mm
5	4	14.16 mm	44.5 mm
6	5	14.45 mm	45.4 mm
7	6	14.74 mm	46.3 mm
8	7	15.04 mm	47.2 mm
9	8	15.33 mm	48.2 mm
10	9	15.62 mm	49.1 mm
11	10	15.91 mm	50.0 mm
12	11	16.20 mm	50.9 mm
13	12	16.50 mm	51.8 mm
14	13	16.79 mm	52.7 mm
15	14	17.08 mm	53.7 mm
16	15	17.37 mm	54.6 mm
17	15	17.66 mm	55.5 mm
18	16	17.95 mm	56.4 mm
19	17	18.25 mm	57.3 mm
20	18	18.54 mm	58.2 mm
21	19	18.83 mm	59.2 mm
22	20	19.12 mm	60.1 mm
23	21	19.41 mm	61.0 mm
24	22	19.71 mm	61.9 mm
25	23	20.00 mm	62.8 mm
26	24	20.29 mm	63.7 mm
27	25	20.58 mm	64.7 mm

Measure in the evening — fingers swell through the day and in heat — and let your jeweller's own chart take precedence over this one. How to measure at home →