Japan to US Ring Size

Enter a Japan size to find its US/Canada equivalent, or scan the reference table below.

Need to convert in reverse? Go to US to Japan Ring Size Converter →

Common Japan to US equivalents

These examples share the same inner diameter. Use the calculator for another size or an in-between measurement.

Japan 9 corresponds to US 5 at 15.7 mm.
Japan 14 corresponds to US 7 at 17.32 mm.
Japan 18 corresponds to US 9 at 18.95 mm.

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Numeric size (e.g. 8) for US/Canada, EU, or Japan — or a letter size (e.g. P 1/2) for UK/Australia.

Japan and US ring sizes use different numeric scales

Japan and US/Canada both use numbers, but those numbers describe different sizing scales. Match through the ring's inside diameter rather than comparing the labels directly. Japan values are a close estimate in this range; confirm the current retailer chart before ordering, especially at the largest sizes.

Japan to US reference table

Japan to US ring size conversion
JapanJP, CN, KR, HK, SG	US / CanadaUS, CA, MX	Diameter (mm)
JapanJP, CN, KR, HK, SG4	US / CanadaUS, CA, MX3	Diameter (mm)14.07
JapanJP, CN, KR, HK, SG6	US / CanadaUS, CA, MX3.5	Diameter (mm)14.48
JapanJP, CN, KR, HK, SG7	US / CanadaUS, CA, MX4	Diameter (mm)14.88
JapanJP, CN, KR, HK, SG8	US / CanadaUS, CA, MX4.5	Diameter (mm)15.29
JapanJP, CN, KR, HK, SG9	US / CanadaUS, CA, MX5	Diameter (mm)15.7
JapanJP, CN, KR, HK, SG10	US / CanadaUS, CA, MX5.5	Diameter (mm)16.1
JapanJP, CN, KR, HK, SG11	US / CanadaUS, CA, MX6	Diameter (mm)16.51
JapanJP, CN, KR, HK, SG13	US / CanadaUS, CA, MX6.5	Diameter (mm)16.92
JapanJP, CN, KR, HK, SG14	US / CanadaUS, CA, MX7	Diameter (mm)17.32
JapanJP, CN, KR, HK, SG15	US / CanadaUS, CA, MX7.5	Diameter (mm)17.73
JapanJP, CN, KR, HK, SG16	US / CanadaUS, CA, MX8	Diameter (mm)18.14
JapanJP, CN, KR, HK, SG17	US / CanadaUS, CA, MX8.5	Diameter (mm)18.54
JapanJP, CN, KR, HK, SG18	US / CanadaUS, CA, MX9	Diameter (mm)18.95
JapanJP, CN, KR, HK, SG19	US / CanadaUS, CA, MX9.5	Diameter (mm)19.35
JapanJP, CN, KR, HK, SG20	US / CanadaUS, CA, MX10	Diameter (mm)19.76
JapanJP, CN, KR, HK, SG22	US / CanadaUS, CA, MX10.5	Diameter (mm)20.17
JapanJP, CN, KR, HK, SG23	US / CanadaUS, CA, MX11	Diameter (mm)20.57
JapanJP, CN, KR, HK, SG24	US / CanadaUS, CA, MX11.5	Diameter (mm)20.98
JapanJP, CN, KR, HK, SG25	US / CanadaUS, CA, MX12	Diameter (mm)21.39
JapanJP, CN, KR, HK, SG26	US / CanadaUS, CA, MX12.5	Diameter (mm)21.79
JapanJP, CN, KR, HK, SG27	US / CanadaUS, CA, MX13	Diameter (mm)22.2

Lower-confidence data — Japan comes from a single published retailer source, or is known to drift by 1–2 sizes at the top of the range. Confirm with the retailer before ordering.