Ring Size Guide
US & Canada Ring Sizes
| US Size | Diameter (mm) | Circumference (mm) |
|---|---|---|
| 3 | 14.1 | 44.2 |
| 3.5 | 14.5 | 45.5 |
| 4 | 14.9 | 46.8 |
| 4.5 | 15.3 | 48.0 |
| 5 | 15.7 | 49.3 |
| 5.5 | 16.1 | 50.6 |
| 6 | 16.5 | 51.9 |
| 6.5 | 16.9 | 53.1 |
| 7 | 17.3 | 54.4 |
| 7.5 | 17.7 | 55.7 |
| 8 | 18.2 | 57.0 |
| 8.5 | 18.6 | 58.3 |
| 9 | 19.0 | 59.5 |
| 9.5 | 19.4 | 60.8 |
| 10 | 19.8 | 62.1 |
| 10.5 | 20.2 | 63.4 |
| 11 | 20.6 | 64.6 |
| 11.5 | 21.0 | 65.9 |
| 12 | 21.4 | 67.2 |
UK & Australia Ring Sizes
| UK Size | Diameter (mm) | Circumference (mm) |
|---|---|---|
| F | 14.1 | 44.2 |
| G | 14.5 | 45.5 |
| H | 14.9 | 46.8 |
| I | 15.3 | 48.0 |
| J | 15.7 | 49.3 |
| K | 16.1 | 50.6 |
| L | 16.5 | 51.9 |
| M | 16.9 | 53.1 |
| N | 17.3 | 54.4 |
| O | 17.7 | 55.7 |
| P | 18.2 | 57.0 |
| Q | 18.6 | 58.3 |
| R | 19.0 | 59.5 |
| S | 19.4 | 60.8 |
| T | 19.8 | 62.1 |
| U | 20.2 | 63.4 |
| V | 20.6 | 64.6 |
| W | 21.0 | 65.9 |
| X | 21.4 | 67.2 |
European Ring Sizes
| EU Size | Diameter (mm) | Circumference (mm) |
|---|---|---|
| 44 | 14.1 | 44.2 |
| 45 | 14.5 | 45.5 |
| 46 | 14.9 | 46.8 |
| 48 | 15.3 | 48.0 |
| 49 | 15.7 | 49.3 |
| 50 | 16.1 | 50.6 |
| 52 | 16.5 | 51.9 |
| 53 | 16.9 | 53.1 |
| 54 | 17.3 | 54.4 |
| 56 | 17.7 | 55.7 |
| 57 | 18.2 | 57.0 |
| 58 | 18.6 | 58.3 |
| 60 | 19.0 | 59.5 |
| 61 | 19.4 | 60.8 |
| 62 | 19.8 | 62.1 |
| 63 | 20.2 | 63.4 |
| 65 | 20.6 | 64.6 |
| 66 | 21.0 | 65.9 |
| 67 | 21.4 | 67.2 |
Japanese Ring Sizes
| JP Size | Diameter (mm) | Circumference (mm) |
|---|---|---|
| 4 | 14.5 | 45.5 |
| 5 | 14.9 | 46.8 |
| 6 | 15.3 | 48.0 |
| 7 | 15.7 | 49.3 |
| 8 | 16.1 | 50.6 |
| 9 | 16.5 | 51.9 |
| 10 | 16.9 | 53.1 |
| 11 | 17.3 | 54.4 |
| 12 | 17.7 | 55.7 |
| 13 | 18.2 | 57.0 |
| 14 | 18.6 | 58.3 |
| 15 | 19.0 | 59.5 |
| 16 | 19.4 | 60.8 |
| 17 | 19.8 | 62.1 |
| 18 | 20.2 | 63.4 |
| 19 | 20.6 | 64.6 |
| 20 | 21.0 | 65.9 |
| 21 | 21.4 | 67.2 |
Find Your Ring Size
Measure Your Finger
- Use a flexible measuring tape or length of string.
- Wrap it around the finger you'll wear your ring on. If you're creating a ring stack, consider where on your finger the ring will sit. If using string, mark the point on the string where the ends meet with a pen.
- Lay the string on a flat surface and use a ruler to measure the length (in inches or millimeters) up to the mark. Compare your measurement to the size chart to determine your ring size. If you are between sizes, opt for the larger size.
Measure an Existing Ring
- Choose a ring that already fits your finger well.
- Measure the interior diameter of the ring in millimeters (mm).
- Use the measurement chart to match the size of your ring to the closest size in mm. The interior of the ring should align with the outer edge of the circle.
Luther's At Your Service
There's no question too small or request too large for Luther's Diamonds client advisors. From choosing an engagement ring or gift to providing in-store or virtual appointments, we're always at your service.
Watch how your ring is made.
Every ring that leaves our studio passes through these stages — cast, ground, set, and hand-polished. Not by a factory line. By the same small team, in the same small workshop, for over a decade.
Grinding After Casting
Once the gold is cast in its rough form, every surface is carefully ground down by hand to reveal the ring's true silhouette.
Setting the Stones
Each stone is placed by hand and secured into its setting — one at a time, under magnification, with full attention to symmetry and seat.
Hand Polished
We still hand-polish every ring. No tumblers, no shortcuts. The mirror finish you see is the result of progressively finer abrasives, worked by hand until the metal sings.
Finished Ring
Before it ships, every ring is inspected one last time by Jack — checking the stone seat, the polish, the comfort of the band — and only then does it leave the workshop.
