Ring Size Converter
Convert between international ring sizes instantly with our accurate sizing tool. Find your perfect fit for US, UK, EU, and Japanese ring sizes.
Diameter & Circumference Converter
International Size Converter
Accurate Ring Sizing Guide
Finding the perfect ring size is essential for comfort and security. Our ring size converter tool helps you accurately determine your size across different international standards. Whether you’re shopping for engagement rings, wedding bands, or fashion jewelry, knowing your precise ring size ensures a perfect fit.
Ring sizing varies by country, with the United States and Canada using numerical sizes, the United Kingdom using alphabetical sizes, Europe using numerical sizes based on circumference, and Japan using a different numerical system. Our converter accounts for all these variations to provide accurate conversions.
Ring Sizing Tips:
- Measure your finger at the end of the day when fingers are typically at their largest
- Consider the width of the ring band – wider bands often require a slightly larger size
- Your dominant hand usually has slightly larger fingers than your non-dominant hand
- Temperature affects finger size – fingers shrink in cold weather and expand in heat
- When between sizes, it’s generally better to choose the larger size for comfort
International Ring Size Chart
| US/Canada | UK/Ireland | Europe | Japan | Diameter (mm) | Circumference (mm) |
|---|---|---|---|---|---|
| 4 | H½ | 47.5 | 9 | 15.3 | 48.0 |
| 5 | J½ | 49.5 | 11 | 16.1 | 50.6 |
| 6 | L½ | 51.5 | 13 | 16.9 | 53.1 |
| 7 | N½ | 54.0 | 14 | 17.3 | 54.4 |
| 8 | P½ | 56.5 | 16 | 18.1 | 56.9 |
| 9 | R½ | 59.0 | 18 | 19.0 | 59.7 |
Frequently Asked Questions
You can measure your ring size at home using a piece of string or paper. Wrap it around the base of your finger, mark where it overlaps, then measure the length in millimeters. Use our diameter/circumference converter with this measurement to find your size.
Different countries developed their own sizing systems independently. The US system is based on a numerical scale, the UK uses letters, Europe uses the inner circumference in millimeters, and Japan has its own numerical system. These differences make conversion tools essential for international jewelry shopping.
The most accurate method is to visit a professional jeweler who can measure your finger with precision tools. For at-home measurements, using a plastic ring sizer or measuring an existing ring that fits well provides good accuracy.
Yes, finger size can change due to factors like weight fluctuations, pregnancy, arthritis, temperature, and even time of day. It’s a good idea to measure your ring size periodically, especially before making significant jewelry purchases.
If you’re between sizes, it’s generally recommended to choose the larger size for comfort. Rings with wider bands (over 6mm) typically feel tighter, so you might need to go up half a size for wider bands compared to thinner ones.
Note: This ring size converter provides approximate conversions. For the most accurate sizing, consult with a professional jeweler.