US to UK ring size converter
US and UK ring sizes use completely different scales. The US system is numeric with half sizes, while the UK, Ireland, Australia and New Zealand use letters from A to Z. A US 7, for example, is a UK N½. Enter a size below to convert either direction, or use the full chart underneath.
Quick answer
A US 7 is N½ in UK (about 54.4 mm inner circumference). Use the converter for your exact size, or the chart below for the full range.
Between two sizes? Size up for a comfortable fit, see how to measure accurately.
US → UK at a glance
- 4 = H½
- 5 = J½
- 6 = L½
- 7 = N½
- 8 = P½
- 9 = R½
- 10 = T½
- 11 = V½
US to UK ring size chart
| USUS / Canada | UKUK / AU | mmCircumference | mmDiameter |
|---|---|---|---|
| 4 | H½ | 46.7 | 14.9 |
| 4½ | I½ | 48.0 | 15.3 |
| 5 | J½ | 49.3 | 15.7 |
| 5½ | K½ | 50.5 | 16.1 |
| 6 | L½ | 51.8 | 16.5 |
| 6½ | M½ | 53.1 | 16.9 |
| 7 | N½ | 54.4 | 17.3 |
| 7½ | O½ | 55.6 | 17.7 |
| 8 | P½ | 56.9 | 18.1 |
| 8½ | Q½ | 58.2 | 18.5 |
| 9 | R½ | 59.5 | 18.9 |
| 9½ | S½ | 60.7 | 19.3 |
| 10 | T½ | 62.0 | 19.7 |
| 10½ | U½ | 63.3 | 20.1 |
| 11 | V½ | 64.6 | 20.5 |
| 11½ | W½ | 65.8 | 21.0 |
| 12 | X½ | 67.1 | 21.4 |
Common questions
How do I convert a US ring size to UK?
Enter your US size in the converter above and read the UK result, or find your row in the chart below. Every value is calculated from the ring’s inner circumference, so it works in both directions.
What is a US 7 in UK?
A US 7 is N½ in UK. That ring has an inner circumference of about 54.4 mm.
Related conversions
Or see the full ring size chart.