Ring Size Converter
Convert between ring size systems including US, UK, EU, and circumference in millimeters.
Equivalent Ring Sizes
7
US
N
UK
54
EU
54.4
mm
Complete Ring Size Chart
| US | UK | EU | Circumference (mm) |
|---|---|---|---|
| 3 | F | 44 | 44.2 |
| 3.5 | G | 45 | 45.5 |
| 4 | H | 47 | 46.8 |
| 4.5 | I | 48 | 48.0 |
| 5 | J | 49 | 49.3 |
| 5.5 | K | 51 | 50.6 |
| 6 | L | 52 | 51.9 |
| 6.5 | M | 53 | 53.1 |
| 7 | N | 54 | 54.4 |
| 7.5 | O | 56 | 55.7 |
| 8 | P | 57 | 57.0 |
| 8.5 | Q | 58 | 58.3 |
| 9 | R | 59 | 59.5 |
| 9.5 | S | 61 | 60.8 |
| 10 | T | 62 | 62.1 |
| 10.5 | U | 63 | 63.4 |
| 11 | V | 65 | 64.6 |
| 11.5 | W | 66 | 65.9 |
| 12 | X | 67 | 67.2 |
| 12.5 | Y | 68 | 68.5 |
| 13 | Z | 70 | 69.7 |
How to Measure Ring Size
1. Wrap a piece of string or paper around the base of your finger
2. Mark where the string/paper overlaps
3. Measure the length in millimeters
4. Use the chart above to find your ring size
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
📚
Formula Source: NIST Guide to SI Units
by National Institute of Standards
🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.