ring size chart

Ring size chart (inner diameter, circumference, international standard)

This is a list of ring sizes, inner diameters, inner circumferences (finger circumference), and international standards.
Monatelier rings are manufactured to the JCS (Japan Custom Size) standard, which is widely used in Japan. We carry out strict size inspections at the same level as top brands.

Japan (number)	Ring inner diameter (mm)	Inner circumference/finger circumference (mm)	International Standards
No. 1	13.0	40.8	41
No. 2	13.3	41.9	42
No. 3	13.7	42.9	43
No. 4	14.0	44.0	44
No. 5	14.3	45.0	45
No. 6	14.7	46.1	46
No. 7	15.0	47.1	47
No. 8	15.3	48.1	48
No. 9	15.7	49.2	49
No. 10	16.0	50.3	50
No. 11	16.3	51.3	51
No. 12	16.7	52.4	52
No. 13	17.0	53.4	53
No. 14	17.3	54.5	54
No. 15	17.7	55.5	55
No. 16	18.0	56.6	56
No. 17	18.3	57.6	57
No. 18	18.7	58.6	58
No. 19	19.0	59.7	59
No. 20	19.3	60.7	60
No. 21	19.7	61.8	61
No. 22	20.0	62.8	62
No. 23	20.3	63.9	63
No. 24	20.7	64.9	64
No. 25	21.0	66.0	65
No. 26	21.3	67.0	66
No. 27	21.7	68.1	67
No. 28	22.0	69.1	68
No. 29	22.3	70.2	69
No. 30	22.7	71.2	70

- If you want to measure the exact size, please use a ring gauge.

Monatelier offers ring sizes from 1 to 16.
Use the filters to find the size you want.
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Chainrings up to size 18 are available.
You can wear it without worrying about the size.
View our chainring collection