Ring Size Converter
Convert a known ring size from one system to another. Start with US, UK, EU/ISO, India, diameter, circumference, cm, or inches.
US 7 is about US 7, UK N 1/2, EU 54.
Thin band chart size, with no fit adjustment.
Converted sizes
- US / Canada
- 7
- UK / Australia
- N 1/2
- EU / ISO
- 54
- Japan / China
- 14
- India
- 14
- Diameter
- 17.3 mm
- Circumference (mm)
- 54.4 mm
- Circumference (in)
- 2.142 in
Computed with the same conversion engine as the Ring Sizer app. Use thin band for pure chart conversion; use a wider band when you want a fit recommendation.
Common conversions
| US | UK | EU | Diameter | Circumference |
|---|---|---|---|---|
| 5 | J 1/2 | 49 | 15.7 mm | 49.3 mm |
| 6 | L 1/2 | 52 | 16.5 mm | 51.9 mm |
| 7 | N 1/2 | 54 | 17.3 mm | 54.4 mm |
| 8 | P 1/2 | 57 | 18.1 mm | 57.0 mm |
| 9 | R 1/2 | 60 | 18.9 mm | 59.5 mm |
| 10 | T 1/2 | 62 | 19.8 mm | 62.1 mm |
FAQ
What is a US size 7 in UK and EU sizes?
A US size 7 is about UK N 1/2 and EU 54.
Is EU ring size the same as millimeters?
Yes. EU/ISO ring size is the inner circumference rounded to the nearest millimeter.
Can I convert UK letters to US sizes?
Yes. Enter a UK size such as N 1/2 and the converter returns the closest US, EU, Japan, India, diameter, and circumference.
How do I convert cm to a ring size?
Measure the inner circumference in centimeters and enter it above. The converter also accepts millimeters and inches. As a reference, 5.4 cm is about a US 7 and 5.7 cm is about a US 8.
What is my US ring size in UK letters?
Enter any US size to see the UK letter instantly. For example, US 6 is about UK L 1/2, US 7 is about UK N 1/2, and US 8 is about UK P 1/2.
Get your exact size, without the jeweler
This converter turns one known size into every system. To find the size in the first place, the app measures it right on screen and converts instantly, the most accurate option short of a trip to the jeweler.
Download Ring Sizer- Free
- iOS
- No sign-up
- Works offline
