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.
Published by Ring Sizer · App developer: Pawel Boguta · Updated
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
- 14
- India
- 14
- Diameter
- 17.3 mm
- Circumference (mm)
- 54.4 mm
- Circumference (in)
- 2.142 in
Uses the Ring Sizer conversion model. Measured values and nominal size conversions can round differently. Use thin band for a chart conversion. See our methodology and supported ranges.
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?
Our UK lookup supports US sizes 4 through 13. 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. A dash means the size is outside the supported UK range.
Sources and methodology
Read our conversion rules, supported ranges, and measurement limitations.
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.
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