Ring Size Conversion Chart
Convert between US, UK, EU, and Japanese ring sizes. Select the systems you need, then print or bookmark your custom chart.
Size systems to display
| Diameter (mm) | US |
|---|---|
| 12.37 | 1 |
| 12.78 | 1.5 |
| 13.21 | 2 |
| 13.61 | 2.5 |
| 14.05 | 3 |
| 14.45 | 3.5 |
| 14.86 | 4 |
| 15.27 | 4.5 |
| 15.70 | 5 |
| 16.10 | 5.5 |
| 16.51 | 6 |
| 16.92 | 6.5 |
| 17.35 | 7 |
| 17.75 | 7.5 |
| 18.19 | 8 |
| 18.53 | 8.5 |
| 18.89 | 9 |
| 19.41 | 9.5 |
| 19.84 | 10 |
| 20.20 | 10.5 |
| 20.68 | 11 |
| 21.08 | 11.5 |
| 21.49 | 12 |
| 21.89 | 12.5 |
| 22.33 | 13 |
| 22.73 | 13.5 |
| 23.06 | 14 |
| 23.47 | 14.5 |
| 23.87 | 15 |
| 24.27 | 15.5 |
| 24.64 | 16 |
12.37 mm
US: 1
12.78 mm
US: 1.5
13.21 mm
US: 2
13.61 mm
US: 2.5
14.05 mm
US: 3
14.45 mm
US: 3.5
14.86 mm
US: 4
15.27 mm
US: 4.5
15.70 mm
US: 5
16.10 mm
US: 5.5
16.51 mm
US: 6
16.92 mm
US: 6.5
17.35 mm
US: 7
17.75 mm
US: 7.5
18.19 mm
US: 8
18.53 mm
US: 8.5
18.89 mm
US: 9
19.41 mm
US: 9.5
19.84 mm
US: 10
20.20 mm
US: 10.5
20.68 mm
US: 11
21.08 mm
US: 11.5
21.49 mm
US: 12
21.89 mm
US: 12.5
22.33 mm
US: 13
22.73 mm
US: 13.5
23.06 mm
US: 14
23.47 mm
US: 14.5
23.87 mm
US: 15
24.27 mm
US: 15.5
24.64 mm
US: 16
Tips
- To measure your ring size at home, wrap a strip of paper around your finger, mark where it overlaps, and measure the length in mm — that’s your EU size.
- Wide bands (8mm+) need a larger size to slide over the knuckle. Use our ring blank calculator to account for this.
- When in doubt, size up — a ring that’s slightly loose is more comfortable than one that’s stuck.
How It Works
Ring sizing systems vary by country, but they all describe the same physical measurement — the inner diameter (or circumference) of the ring. This chart converts between the four most common systems:
- US — arbitrary numbers (1–16 in half sizes), based on a standardized mandrel
- UK — letters A–Z, used in the United Kingdom, Ireland, and Australia
- EU — the inner circumference of the ring in millimeters, rounded to the nearest integer
- JP — numbered system used in Japan (JIS standard)
Because all systems describe the same physical measurement (inner diameter), converting between them is a straightforward lookup — no math required on your part.