EU ring size 70 in US, UK & Japan

EU/ISO ring size 70 is an inner circumference of about 70 mm (69.7 mm exactly) — that equals US 13, UK Z½ and Japan 27, with an inner diameter of 22.20 mm.

Illustrative — screen scale varies. Use the true-scale ring below for a real measurement.

EU / ISO: 70
US / Canada: 13
UK / AU: Z½
Japan: 27
CH / IT / ES: 30
Diameter: 22.20 mm
Circumference: 69.7 mm

Why EU 70 looks larger than US 13

Under ISO 8653, the EU (and ISO) ring size number is the ring's inner circumference in millimetres. So EU 70 means the band measures about 70 mm all the way around — a circumference, not a diameter. That's why EU numbers are so much larger than US numbers for the same finger, and why an EU size can be read straight off a millimetre measurement.

50 mm reference bar

True-to-scale ring Printed at 100%, the inside of this ring is 22.20 mm across.

Convert the other way with the EU to US ring size chart, open the US size 13 page, see the full chart, or use the converter.

Frequently asked questions

Why does EU 70 use a circumference number?

EU/ISO 70 follows the published circumference convention: about 70 mm around the inside (69.7 mm in this chart), corresponding to a 22.20 mm inner diameter.

How should I confirm EU 70 before ordering?

Check the retailer's own chart and confirm the 22.20 mm inner diameter with a physical sizer or a ring that already fits. Converted labels are a starting point, not a fit guarantee.