Convert US Ring Sizes to Millimeters of Circumference
1 us / canada size = 39.0905 millimeters of circumference. Multiply by 2.5535, then + 36.537.
1 US = 39.0905 mm
Multiply by 2.5535, then + 36.537.
Fingers change size with temperature and time of day, and wide bands fit tighter. Have a jeweller confirm before buying. About accuracy
US Ring Sizes to Millimeters of Circumference table
| US Ring Sizes | Millimeters of Circumference |
|---|---|
| 1 US | 39.0905 mm |
| 2 US | 41.644 mm |
| 3 US | 44.1975 mm |
| 4 US | 46.751 mm |
| 5 US | 49.3045 mm |
| 10 US | 62.072 mm |
| 20 US | 87.607 mm |
| 25 US | 100.3745 mm |
| 50 US | 164.212 mm |
| 100 US | 291.887 mm |
| 500 US | 1,313.287 mm |
| 1000 US | 2,590.037 mm |
About these units
The us / canada size (US) is a US customary unit of ring size.
The inner circumference (mm) (mm) is a metric unit of ring size.
Going the other way, 1 inner circumference (mm) = -13.916977 us ring sizes. Ring sizes are all derived from the inner circumference of the band. The US scale adds about 2.55 mm of circumference per size, the ISO standard quotes the circumference in millimetres directly, and France and Spain quote the circumference minus 40. Measure a ring that already fits rather than your finger, at room temperature.
Frequently asked
- How many millimeters of circumference are in a us / canada size?
- 1 us / canada size = 39.0905 millimeters of circumference.
- How do you convert us ring sizes to millimeters of circumference?
- Multiply by 2.5535, then + 36.537.
- What is 10 US in mm?
- 10 US = 62.072 mm.