Ring Size Converter
Convert between UK, US, EU and Japanese ring sizes plus circumference and diameter in mm. Includes a guide on how to measure your ring size at home.
Enter a Size
Equivalent Sizes
UK
M
US
7
EU
53
Japanese
13
Circumference
49.4mm
Diameter
15.7mm
Complete Ring Size Chart
| UK | US | EU | JP | Circumference | Diameter |
|---|---|---|---|---|---|
| A | 1 | 41 | 1 | 36.2mm | 11.5mm |
| B | 1.5 | 42 | 2 | 37.3mm | 11.9mm |
| C | 2 | 43 | 3 | 38.4mm | 12.2mm |
| D | 2.5 | 44 | 4 | 39.5mm | 12.6mm |
| E | 3 | 45 | 5 | 40.6mm | 12.9mm |
| F | 3.5 | 46 | 6 | 41.7mm | 13.3mm |
| G | 4 | 47 | 7 | 42.8mm | 13.6mm |
| H | 4.5 | 48 | 8 | 43.9mm | 14mm |
| I | 5 | 49 | 9 | 45mm | 14.3mm |
| J | 5.5 | 50 | 10 | 46.1mm | 14.7mm |
| K | 6 | 51 | 11 | 47.2mm | 15mm |
| L | 6.5 | 52 | 12 | 48.3mm | 15.4mm |
| M | 7 | 53 | 13 | 49.4mm | 15.7mm |
| N | 7.5 | 54 | 14 | 50.5mm | 16.1mm |
| O | 8 | 55 | 15 | 51.6mm | 16.4mm |
| P | 8.5 | 56 | 16 | 52.7mm | 16.8mm |
| Q | 9 | 57 | 17 | 53.8mm | 17.1mm |
| R | 9.5 | 58 | 18 | 54.9mm | 17.5mm |
| S | 10 | 59 | 19 | 56mm | 17.8mm |
| T | 10.5 | 60 | 20 | 57.1mm | 18.2mm |
| U | 11 | 61 | 21 | 58.2mm | 18.5mm |
| V | 11.5 | 62 | 22 | 59.3mm | 18.9mm |
| W | 12 | 63 | 23 | 60.4mm | 19.2mm |
| X | 12.5 | 64 | 24 | 61.5mm | 19.6mm |
| Y | 13 | 65 | 25 | 62.6mm | 19.9mm |
| Z | 13.5 | 66 | 26 | 63.7mm | 20.3mm |
How to Measure Your Ring Size
- With a ring you wear: Measure the inner diameter with calipers
- With string or tape: Wrap around your finger (knuckle), measure circumference
- At a jeweller: They have a proper ring sizer tool (most accurate)
- Measure when your hands are warm and at the end of the day (fingers swell)
- Most people are a size M-R (UK) or 6-10 (US)