US to EU ring size converter
The European system is the easiest to understand: under ISO 8653, the EU size number IS the ring’s inner circumference in millimetres. So an EU 54 ring measures 54 mm around the inside. A US 7 works out to about EU 54. Convert your size below.
Quick answer
A US 7 is 54 in EU (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 → EU at a glance
- 4 = 47
- 5 = 49
- 6 = 52
- 7 = 54
- 8 = 57
- 9 = 59
- 10 = 62
- 11 = 65
US to EU ring size chart
| USUS / Canada | EUEU / ISO | mmCircumference | mmDiameter |
|---|---|---|---|
| 4 | 47 | 46.7 | 14.9 |
| 4½ | 48 | 48.0 | 15.3 |
| 5 | 49 | 49.3 | 15.7 |
| 5½ | 51 | 50.5 | 16.1 |
| 6 | 52 | 51.8 | 16.5 |
| 6½ | 53 | 53.1 | 16.9 |
| 7 | 54 | 54.4 | 17.3 |
| 7½ | 56 | 55.6 | 17.7 |
| 8 | 57 | 56.9 | 18.1 |
| 8½ | 58 | 58.2 | 18.5 |
| 9 | 59 | 59.5 | 18.9 |
| 9½ | 61 | 60.7 | 19.3 |
| 10 | 62 | 62.0 | 19.7 |
| 10½ | 63 | 63.3 | 20.1 |
| 11 | 65 | 64.6 | 20.5 |
| 11½ | 66 | 65.8 | 21.0 |
| 12 | 67 | 67.1 | 21.4 |
The EU number is a measurement, not a code
This is the part that surprises people. A European ring size is not a position on an invented scale, it is the ring’s inner circumference in millimetres. An EU 54 ring measures 54 mm around the inside. Nothing is hidden and nothing needs decoding.
That makes European sizes the most transparent of the four main systems, and it is why this site uses circumference as the value everything else is calculated from. Convert a US size to millimetres and you have already found the European size.
Why the EU numbers seem to skip
Work down a US to EU chart and the European column jumps unevenly: 52, 54, 57, 59. Nothing is wrong. US sizes are spaced 2.55 mm apart while European sizes are whole millimetres, so each step up the US scale advances the European number by two or three.
The flip side is that several European sizes sit between two US sizes with no US equivalent at all. An EU 55 works out to a US 7.25, which is a real gap in the American scale rather than a rounding quirk. A European jeweller can make that size even though a US size chart has no name for it.
Buying from European jewellers
French, German and Scandinavian jewellers quote this circumference number directly, so a size given in Paris will match one given in Berlin. Italy, Spain and Switzerland are the exception: they often quote the circumference minus 40, so an EU 54 is written as a 14. If a European size looks far too small to be a circumference, that is almost always what you are looking at.
Because European sizing is quoted in whole millimetres, it is worth measuring carefully before ordering. A single millimetre is roughly a third of a US size.
Common questions
How do I convert a US ring size to EU?
Enter your US size in the converter above and read the EU 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 EU?
A US 7 is 54 in EU. That ring has an inner circumference of about 54.4 mm.
Related conversions
Or see the full ring size chart.