Ringsizely

Ring size 5.5 in millimetres

US ring size 5.5 is 16.10 mm inner diameter and 50.6 mm circumference.

16.10 mm inner Ø
Proportional only — actual on-screen size depends on your display.
US / CA
5.5
UK / AU
K½
EU / ISO
51
Japan
10
CH / IT / ES
11
Ø in
0.634
50 mm reference
Actual-size print check Inner diameter: 16.10 mm. Print at 100% and verify the 50 mm reference bar before comparing a ring.

This is around the average women’s ring size (US 6–6½). See the full international ring size chart · Converter

Frequently asked questions

What is ring size 5.5 in mm?

US ring size 5.5 has an inner diameter of 16.10 mm and an inner circumference of 50.6 mm.

What is US 5.5 in UK, EU and Japan ring sizes?

US 5.5 converts to UK K½, EU/ISO 51, Japan 10, and Switzerland/Italy/Spain 11.

Is ring size 5.5 small or large?

This is around the average women’s ring size (US 6–6½).