Every ring we make is listed by its letter size and its inside diameter in millimetres (Ø). The table converts both to US and EU sizes.
How to measure
Take a ring that already fits the finger you want to wear it on. Measure straight across the inside, edge to edge, in millimetres. Find that number in the Ø column. If you land between two sizes, pick the larger one.
Size charts vary a little from brand to brand, because the sizing standard allows a tolerance of 0.1mm to 0.25mm. Always check the chart of the shop you buy from.
| Ø (mm) | UK | US | EU |
|---|---|---|---|
| 13.9 | F | 3 | 44 |
| 14.3 | G | 3.5 | 45.5 |
| 14.7 | H | 4 | 46.8 |
| 15.1 | I | 4.5 | 48 |
| 15.5 | J | 5 | 49.3 |
| 15.9 | K | 5.5 | 50.6 |
| 16.3 | L | 6 | 51.8 |
| 16.7 | M | 6.5 | 53.1 |
| 17.1 | N | 7 | 54.4 |
| 17.5 | O | 7.5 | 55.7 |
| 17.9 | P | 8 | 57 |
| 18.3 | Q | 8.5 | 58.3 |
| 18.7 | R | 9 | 59.5 |
| 19.1 | S | 9.5 | 60.8 |
| 19.5 | T | 10 | 62.1 |
| 19.9 | U | 10.5 | 63.4 |
| 20.3 | V | 11 | 64.6 |
| 20.7 | W | 11.5 | 65.9 |
| 21.1 | X | 12 | 67.2 |
| 21.5 | Y | 12.5 | 68.5 |
| 21.9 | Z | 13 | 69.7 |
| 22.3 | Z+1 | 13.5 | 71 |
| 22.7 | Z+2 | 14 | 72.3 |
| 23.1 | Z+3 | 14.5 | 73.6 |
Returns and exchanges
You can return a ring within 14 days of delivery. If it doesn't fit, send it back unworn within 30 days and we'll exchange it for another size where we can. Email hello@projectatomic.com with your order number before you post anything. See our returns policy for the details.