Ringsizely

Ring size 12 in millimetres

US ring size 12 is 21.39 mm inner diameter and 67.2 mm circumference.

21.39 mm inner Ø
Proportional only — actual on-screen size depends on your display.
US / CA
12
UK / AU
Y
EU / ISO
67
Japan
25
CH / IT / ES
27
Ø in
0.842
C (in)
2.646
Actual-size print check Inner diameter: 21.39 mm. Print at 100% and verify the 50 mm reference bar before comparing a ring.

A size label alone does not predict fit. Measure the exact finger and hand, and check the band width before ordering. See the full international ring size chart · Converter

Convert size 12: UK · EU · Japan

Frequently asked questions

Is ring size 12 small or large?

A size label alone does not predict fit. Measure the exact finger and hand, and check the band width before ordering.

I am between sizes — should I size up or down?

Measure again at a different time. If the result stays between sizes, compare band width, knuckle clearance, and the retailer's chart before choosing. A wider band can feel tighter than a narrow one at the same labelled size.

How should I confirm a converted ring size before ordering?

Measure the same finger or a ring that fits with a second method. For an expensive, wide, or non-resizable ring, check the retailer's chart and confirm with a physical sizer or jeweller.