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Ring size 11½ in mm and international sizes

A US/Canadian size 11½ ring is 21.0 mm across the inside and 65.9 mm around. Larger sizes are stocked less often; check that a design is offered this large before falling for it.

34567891011121311½
US / Canada
11½
UK / Australia
W½
EU / ISO
66
Japan / China
24
India
26
Italy / Spain / CH
26
Inside diameter
21.0 mm
Circumference
65.9 mm
Diameter (in)
0.826″

Size 11½ and its neighbours

USUKEUJapanDiameterCircumference
11V½652320.57 mm64.6 mm
11¼W652420.77 mm65.3 mm
11½W½662420.98 mm65.9 mm
11¾X672421.18 mm66.5 mm
12X½672521.38 mm67.2 mm

Check it's really your size

A strip of paper wrapped around your finger should measure 65–67 mm for a size 11½. If you're buying a band 6 mm or wider, consider size 12 instead. Not sure? Try the ring size calculator or the online sizer.

Questions people ask

What is ring size 11½ in mm?

A US size 11½ ring has an inside diameter of 21.0 mm (0.826 in) and an inside circumference of 65.9 mm.

What is a US 11½ in UK and European sizes?

US 11½ is UK/Australian W½ and EU (ISO) 66. In Italy, Spain and Switzerland it is 26.

What is a US 11½ in Japanese sizes?

The nearest Japanese and Chinese size is 24.

How do I know if I'm a size 11½?

Wrap a paper strip around your finger: if it measures about 66 mm, you're a 11½. Or measure a ring that fits: about 21.0 mm across the inside.