Conversion · Japan to United States

Japan / China to US / Canada ring sizes.

Japan / China 14 = US / Canada 6½ 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	US / Canada	Diameter	Circumference
1	outside range	12.99 mm	40.8 mm
2	outside range	13.28 mm	41.7 mm
3	outside range	13.58 mm	42.7 mm
4	3	13.87 mm	43.6 mm
5	3	14.16 mm	44.5 mm
6	3½	14.45 mm	45.4 mm
7	4	14.74 mm	46.3 mm
8	4	15.04 mm	47.2 mm
9	4½	15.33 mm	48.2 mm
10	5	15.62 mm	49.1 mm
11	5½	15.91 mm	50.0 mm
12	5½	16.20 mm	50.9 mm
13	6	16.50 mm	51.8 mm
14	6½	16.79 mm	52.7 mm
15	6½	17.08 mm	53.7 mm
16	7	17.37 mm	54.6 mm
17	7½	17.66 mm	55.5 mm
18	8	17.95 mm	56.4 mm
19	8	18.25 mm	57.3 mm
20	8½	18.54 mm	58.2 mm
21	9	18.83 mm	59.2 mm
22	9	19.12 mm	60.1 mm
23	9½	19.41 mm	61.0 mm
24	10	19.71 mm	61.9 mm
25	10½	20.00 mm	62.8 mm
26	10½	20.29 mm	63.7 mm
27	11	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 →