International Ring Size Chart
Compare ring sizes across countries worldwide. Different regions use different sizing systems — use this chart to convert between them instantly.
Ring Size Systems by Region
North America
US numerical system (sizes 3–15)
United Kingdom & Commonwealth
UK letter system (A–Z+)
Continental Europe
Circumference in mm (44–74)
East Asia
Japanese numerical system (1–33)
Central Europe
Swiss numerical system
Complete International Conversion Table
US / CanadaUS | UK / AustraliaUK | EuropeEU | JapanJP | SwitzerlandCH | Diameter (mm)Dia. | Circumference (mm)Circ. |
|---|---|---|---|---|---|---|
| 3 | F | 44 | 4 | 4 | 14 mm | 44 mm |
| 3.25 | F½ | 44.6 | 5 | 4.5 | 14.2 mm | 44.6 mm |
| 3.5 | G | 45.2 | 5 | 5.25 | 14.4 mm | 45.2 mm |
| 3.75 | G½ | 45.8 | 6 | 5.75 | 14.6 mm | 45.8 mm |
| 4 | H | 46.5 | 7 | 6.5 | 14.8 mm | 46.5 mm |
| 4.25 | H½ | 47.1 | 7 | 7 | 15 mm | 47.1 mm |
| 4.5 | I | 47.7 | 8 | 7.75 | 15.2 mm | 47.7 mm |
| 4.75 | I½ | 48.3 | 8 | 8.25 | 15.4 mm | 48.3 mm |
| 5 | J | 49 | 9 | 9 | 15.6 mm | 49 mm |
| 5.25 | J½ | 49.6 | 10 | 9.5 | 15.8 mm | 49.6 mm |
| 5.5 | K | 50.2 | 10 | 10.25 | 16 mm | 50.2 mm |
| 5.75 | K½ | 50.8 | 11 | 10.75 | 16.2 mm | 50.8 mm |
| 6 | L | 51.5 | 12 | 11.5 | 16.5 mm | 51.5 mm |
| 6.25 | L½ | 52.1 | 12 | 12 | 16.7 mm | 52.1 mm |
| 6.5 | M | 52.7 | 13 | 12.75 | 16.9 mm | 52.7 mm |
| 6.75 | M½ | 53.3 | 13 | 13.25 | 17.1 mm | 53.3 mm |
| 7 | N | 54 | 14 | 14 | 17.3 mm | 54 mm |
| 7.25 | N½ | 54.6 | 14 | 14.5 | 17.5 mm | 54.6 mm |
| 7.5 | O | 55.2 | 15 | 15.25 | 17.7 mm | 55.2 mm |
| 7.75 | O½ | 55.8 | 15 | 15.75 | 17.9 mm | 55.8 mm |
| 8 | P | 56.5 | 16 | 16.5 | 18.1 mm | 56.5 mm |
| 8.25 | P½ | 57.1 | 17 | 17 | 18.3 mm | 57.1 mm |
| 8.5 | Q | 57.7 | 17 | 17.75 | 18.5 mm | 57.7 mm |
| 8.75 | Q½ | 58.3 | 18 | 18.25 | 18.7 mm | 58.3 mm |
| 9 | R | 59 | 19 | 19 | 18.9 mm | 59 mm |
| 9.25 | R½ | 59.6 | 19 | 19.5 | 19.1 mm | 59.6 mm |
| 9.5 | S | 60.2 | 20 | 20.25 | 19.2 mm | 60.2 mm |
| 9.75 | S½ | 60.8 | 21 | 20.75 | 19.4 mm | 60.8 mm |
| 10 | T | 61.5 | 22 | 21.5 | 19.6 mm | 61.5 mm |
| 10.25 | T½ | 62.1 | 22 | 22 | 19.8 mm | 62.1 mm |
| 10.5 | U | 62.7 | 23 | 22.75 | 20 mm | 62.7 mm |
| 10.75 | U½ | 63.3 | 23 | 23.25 | 20.2 mm | 63.3 mm |
| 11 | V | 64 | 24 | 24 | 20.4 mm | 64 mm |
| 11.25 | V½ | 64.6 | 24 | 24.5 | 20.6 mm | 64.6 mm |
| 11.5 | W | 65.2 | 25 | 25.25 | 20.8 mm | 65.2 mm |
| 11.75 | W½ | 65.8 | 26 | 25.75 | 21 mm | 65.8 mm |
| 12 | X | 66.5 | 27 | 26.5 | 21.2 mm | 66.5 mm |
| 12.5 | Y | 67.7 | 28 | 27.75 | 21.6 mm | 67.7 mm |
| 13 | Z | 69 | 29 | 29 | 22 mm | 69 mm |
| 13.5 | Z+1 | 70.2 | 30 | 30.25 | 22.3 mm | 70.2 mm |
| 14 | Z+2 | 71.5 | 31 | 31.5 | 22.6 mm | 71.5 mm |
| 14.5 | Z+3 | 72.7 | 32 | 32.75 | 23 mm | 72.7 mm |
| 15 | Z+4 | 74 | 33 | 34 | 23.4 mm | 74 mm |
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Popular Size Comparisons
Quick reference for the most commonly requested conversions.
US 6 = ?
- UK: L
- EU: 51.5
- Japan: 12
- Diameter: 16.5 mm
US 7 = ?
- UK: N
- EU: 54
- Japan: 14
- Diameter: 17.3 mm
US 8 = ?
- UK: P
- EU: 56.5
- Japan: 16
- Diameter: 18.1 mm
US 9 = ?
- UK: R
- EU: 59
- Japan: 19
- Diameter: 18.9 mm
US 10 = ?
- UK: T
- EU: 61.5
- Japan: 22
- Diameter: 19.6 mm
US 11 = ?
- UK: V
- EU: 64
- Japan: 24
- Diameter: 20.4 mm
Frequently Asked Questions
Why do different countries use different ring size systems?
Ring sizing systems developed independently in different regions. The US uses a numerical scale based on inner diameter, the UK uses letters of the alphabet, European countries use the inner circumference in millimeters, and Japan uses a simple numerical scale. These systems reflect historical measurement traditions in each region.
Which countries use the US ring size system?
The US ring size system (numerical, ranging from about 3 to 15) is used in the United States, Canada, and Mexico. It's also widely understood internationally due to the influence of American jewelry brands.
Which countries use the UK ring size system?
The UK letter-based ring size system (A through Z and beyond) is used in the United Kingdom, Ireland, Australia, New Zealand, and South Africa. It's one of the most widely used systems in Commonwealth countries.
How does European ring sizing work?
European ring sizes are based on the inner circumference of the ring measured in millimeters. For example, EU size 54 means the ring's inner circumference is approximately 54 mm. This system is used across most of continental Europe, including France, Germany, Italy, Spain, the Netherlands, and Scandinavia.
Is Japanese ring sizing different from other Asian countries?
Yes, Japan has its own unique ring sizing system with numerical sizes starting from 1. Other Asian countries may use different systems — for example, China often uses a diameter-based system, while Hong Kong uses a system similar to the UK but with slight variations. Always verify which specific system is being used.