Ring Size Converter → Inches to Ring Size Converter
Inches to Ring Size Converter
Measured a ring across the inside in inches? Enter it below to get your size in US, UK, Europe, Japan, and millimeters. Most US ring diameters fall between 0.55 in and 0.87 in.
Enter a measurement above to see your size in every standard.
Inches to Ring Size chart
| Inches (diameter) | MM | US / CA | UK / AU | Europe |
|---|---|---|---|---|
| 0.56" | 14.1 | 3 | F | 44 |
| 0.57" | 14.5 | 3.5 | G | 45½ |
| 0.59" | 14.9 | 4 | H½ | 47 |
| 0.60" | 15.3 | 4.5 | I½ | 48 |
| 0.62" | 15.7 | 5 | J½ | 49 |
| 0.63" | 16.1 | 5.5 | K½ | 50½ |
| 0.65" | 16.5 | 6 | L½ | 52 |
| 0.67" | 16.9 | 6.5 | M½ | 53 |
| 0.68" | 17.3 | 7 | N½ | 54 |
| 0.70" | 17.7 | 7.5 | O½ | 55½ |
| 0.71" | 18.1 | 8 | P½ | 57 |
| 0.73" | 18.5 | 8.5 | Q½ | 58 |
| 0.75" | 19.0 | 9 | R½ | 59½ |
| 0.76" | 19.4 | 9.5 | S½ | 61 |
| 0.78" | 19.8 | 10 | T½ | 62 |
| 0.80" | 20.2 | 10.5 | U½ | 63½ |
| 0.81" | 20.6 | 11 | V½ | 65 |
| 0.83" | 21.0 | 11.5 | W½ | 66 |
| 0.84" | 21.4 | 12 | Y | 67½ |
| 0.86" | 21.8 | 12.5 | Z | 68½ |
| 0.87" | 22.2 | 13 | Z+1 | 70 |
Industry-standard approximations; manufacturers vary slightly. If you're between sizes, round up.
FAQ
What ring size is 0.7 inches?
An inside diameter of about 0.7 inches (17.8 mm) is roughly a US size 7.5. Enter your exact measurement above for the precise match, since a small difference in inches shifts the size.
How do I measure ring diameter in inches?
Lay a ring that fits flat and measure straight across the inside edge with a ruler marked in inches. That inside diameter is what the converter uses. Measuring the inside (not the outside) is important.
Is ring size the diameter or circumference?
Neither directly — ring size is a scale. In the US it's a number, in the UK a letter, and in Europe it equals the inside circumference in millimeters. This tool derives all of them from your diameter.