Ring Size Converter
Convert ring sizes between US, UK, EU, Japan, diameter (mm), and circumference (mm). Complete size chart with instant lookup.
Complete Ring Size Chart
| US | UK | EU | Japan | Dia. (mm) | Circ. (mm) |
|---|---|---|---|---|---|
| 3 | F | 44 | 4 | 14 | 44 |
| 3.5 | G | 45.5 | 5 | 14.4 | 45.5 |
| 4 | H | 47 | 7 | 14.8 | 46.8 |
| 4.5 | I | 48 | 8 | 15.2 | 48 |
| 5 | J | 49 | 9 | 15.6 | 49 |
| 5.5 | K | 50.5 | 10 | 16 | 50.3 |
| 6 | L | 51.5 | 12 | 16.5 | 51.5 |
| 6.5 | M | 52.5 | 13 | 16.9 | 52.8 |
| 7 | N | 54 | 14 | 17.3 | 54 |
| 7.5 | O | 55 | 15 | 17.7 | 55.3 |
| 8 | P | 56.5 | 16 | 18.1 | 56.6 |
| 8.5 | Q | 58 | 17 | 18.5 | 57.8 |
| 9 | R | 59 | 18 | 18.9 | 59.1 |
| 9.5 | S | 60.5 | 19 | 19.4 | 60.3 |
| 10 | T | 61.5 | 20 | 19.8 | 61.6 |
| 10.5 | U | 63 | 22 | 20.2 | 62.8 |
| 11 | V | 64 | 23 | 20.6 | 64.1 |
| 11.5 | W | 65 | 24 | 21 | 65.3 |
| 12 | X | 66.5 | 25 | 21.4 | 66.6 |
| 12.5 | Y | 67.5 | 26 | 21.8 | 67.8 |
| 13 | Z | 69 | 27 | 22.2 | 69.1 |
Click a row to highlight. Click any value in matched result to copy.
How to Use the Ring Size Converter
- Select the sizing system you know (US, UK, EU, Japan, diameter, or circumference).
- Enter your known size value.
- The matching row in the chart will be highlighted.
- Read across the row to find equivalent sizes in all other systems.
Ring Sizing Systems
The US system uses numeric sizes (3-13 in half sizes). The UK uses letters (F-Z). The EU system uses numeric sizes based on circumference in mm. Japan uses its own numeric system. You can also match by the inner diameter or circumference in millimeters for precision measurement.
Features
- Comprehensive size chart from US 3 to US 13
- Six sizing systems: US, UK, EU, Japan, diameter, circumference
- Instant search and highlight
- 100% client-side processing for full privacy
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Disclaimer: This tool is provided as-is for informational and educational purposes only.