Ring Size Guide:
| Measure (mm) | European ring size | UK & US ring size | Japanese ring size |
| 14.65 | 46 | 3 3/4 | 6 |
| 14.97 | 47 | 4 | 7 |
| 15.29 | 48 | 4 1/2 | 8 |
| 15.61 | 49 | 4 3/4 | 9 |
| 15.92 | 50 | 5 1/4 | 10 |
| 16.24 | 51 | 5 3/4 | 11 |
| 16.56 | 52 | 6 | 12 |
| 16.88 | 53 | 6 1/4 | 13 |
| 17.2 | 54 | 6 3/4 | 14 |
| 17.52 | 55 | 7 1/4 | 15 |
| 17.83 | 56 | 7 1/2 | 16 |
| 18.15 | 57 | 8 | 17 |
| 18.47 | 58 | 8 1/4 | 18 |
| 18.79 | 59 | 8 3/4 | 19 |
| 19.11 | 60 | 9 | 20 |
| 19.43 | 61 | 9 1/2 | 21 |
| 19.75 | 62 | 10 | 22 |
Each Forever Ring includes flush-set round diamonds in a mix of 1.0mm and 1.2mm sizes. Diamond count and total carat weight scale subtly with ring size to maintain aesthetic balance:
| Size Category | Stones | W | L | H |
| Sizes 44–48 | 21 stones | 8.9mm | 16.36mm | 1.78mm |
| Sizes 49–53 | 25 stones | 9.9mm | 18.18mm | 1.98mm |
| Sizes 54–60 | 32 stones | 11.1mm | 20.2mm | 2.2mm |