Ring Size Conversion
Convert between US, UK, and ISO (mm) ring sizes.
Conversion Charts
Popular Sizes
How to Measure Ring Size
- Measure at the end of the day when fingers are largest
- Ensure the ring fits over your knuckle
- Measure in normal temperature (fingers swell in heat)
- Consider ring width — wider bands need larger sizes
ISO sizes represent inner circumference in millimeters. This is the international standard for ring sizing.