Ring Size Conversion
Values are approximate. Japan (JIS) inner diameters are measured values; US sizes are mapped to the closest inner diameter.
| Japan (Size) | US | Inner Ø (mm) | Inner Circ. (mm) |
|---|---|---|---|
| 4 | US 3 | 14.0 | 44.0 |
| 5 | US 3.5 | 14.4 | 45.0 |
| 6 | US 3.5-4 | 14.7 | 46.1 |
| 7 | US 4-4.5 | 15.0 | 47.1 |
| 8 | US 4.5-5 | 15.4 | 48.2 |
| 9 | US 5 | 15.7 | 49.2 |
| 10 | US 5.5 | 16.0 | 50.3 |
| 11 | US 6 | 16.4 | 51.3 |
| 12 | US 6.5 | 16.7 | 52.4 |
| 13 | US 6.5-7 | 17.0 | 53.4 |
| 14 | US 7-7.5 | 17.4 | 54.5 |
| 15 | US 7.5-8 | 17.7 | 55.5 |
| 16 | US 8 | 18.0 | 56.6 |
| 17 | US 8.5 | 18.4 | 57.6 |
| 18 | US 9 | 18.7 | 58.6 |
How to Measure & Notes
Wrap a strip of paper or thread around the widest part of the finger you’ll wear the ring on. Mark where it
overlaps,
then measure that length—this is your finger circumference. Compare it with the chart to find your ring
size.
- Finger size can vary slightly with swelling and time of day. Please consider this when choosing your size.
- Sizes may differ between hands; the dominant hand is often slightly larger.
- For wide bands, we recommend choosing one to two sizes up.
