Ring size chart
Updated: 14 July 2026
The European ring size is the inside circumference in millimeters. Size 52 means 52 mm circumference and 16.6 mm inside diameter. The chart lists every size from 44 to 72 mm with diameter, US size and UK letter.
Every ring size at a glance
| Size (circumference) | Diameter | US | UK |
|---|---|---|---|
| 44 mm | 14 mm | US 3 | UK F |
| 45 mm | 14.3 mm | US 3.5 | UK G |
| 46 mm | 14.6 mm | US 3.5 | UK G |
| 47 mm | 15 mm | US 4 | UK H |
| 48 mm | 15.3 mm | US 4.5 | UK I |
| 49 mm | 15.6 mm | US 5 | UK J |
| 50 mm | 15.9 mm | US 5.5 | UK K |
| 51 mm | 16.2 mm | US 5.5 | UK L |
| 52 mm | 16.6 mm | US 6 | UK M |
| 53 mm | 16.9 mm | US 6.5 | UK M |
| 54 mm | 17.2 mm | US 7 | UK N |
| 55 mm | 17.5 mm | US 7 | UK O |
| 56 mm | 17.8 mm | US 7.5 | UK P |
| 57 mm | 18.1 mm | US 8 | UK Q |
| 58 mm | 18.5 mm | US 8.5 | UK Q |
| 59 mm | 18.8 mm | US 9 | UK R |
| 60 mm | 19.1 mm | US 9 | UK S |
| 61 mm | 19.4 mm | US 9.5 | UK T |
| 62 mm | 19.7 mm | US 10 | UK T |
| 63 mm | 20.1 mm | US 10.5 | UK U |
| 64 mm | 20.4 mm | US 11 | UK V |
| 65 mm | 20.7 mm | US 11 | UK W |
| 66 mm | 21 mm | US 11.5 | UK X |
| 67 mm | 21.3 mm | US 12 | UK X |
| 68 mm | 21.6 mm | US 12.5 | UK Y |
| 69 mm | 22 mm | US 12.5 | UK Z |
| 70 mm | 22.3 mm | US 13 | UK above Z |
| 71 mm | 22.6 mm | US 13.5 | UK above Z |
| 72 mm | 22.9 mm | US 14 | UK above Z |
How to find your row
These are the reliable ways to measure:
- Take a ring that already fits the right finger, lay it on a ruler and measure the inside diameter from edge to edge.
- Or use a ring sizer, a set of sample rings you try on one by one.
- Or have a jeweler measure your finger.
The string method (wrap a string around the finger and measure its length) is a fallback for when none of the above is possible. It gives you a rough estimate. Measure the finger you want to wear the ring on and remember that the ring also has to pass your knuckle.
If you have the inside diameter, multiply it by 3.1416 and look for the closest circumference in the chart. If you measured the circumference directly, you can read the size straight off, no math needed.
US and UK in the same row
The US scale counts in its own steps and uses half sizes, the UK uses letters. Both are tied to the inside diameter, so every row of the chart carries the matching value.
Size 52 is about US 6 and UK M. The systems start at different points, so the conversion does not always land on a round number.
Common questions
What does the number in a ring size mean?
In Europe it is the inside circumference of the ring in millimeters. Size 54 means 54 mm circumference, which is 17.2 mm inside diameter.
What is ring size 52 in US and UK sizes?
Size 52 is about US 6 and UK M.
How do I find someone's ring size without asking?
Borrow a ring they already wear on the right finger and measure the inside diameter. 17.2 mm diameter is size 54, for example.