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.
Carved by hand
Details you find later
The kind you notice on the second look, then keep looking for.
- 01 Ocean-wave engravingWaves engraved by hand along the band.
- 02 Marquise + round accentsExtra light that also guards the center stone.
- 03 Open galleryLight passes in under the stone.
Made to go with
What works with The Rapunzel
Shapes, golds and bands we've already made for this setting.
Another shape in mind? Start a custom build- Signature shape MarquiseLong and slender, between the waves.
- Accent stones Diamond, or a color you lovePeridot has been made. Ask us about other colors.
- Gold 14K yellow, white or rose · Platinum 950
Carved & Vintage
Made to look handed down
Engraving, milgrain and old cuts, made new at our bench.
Every order, not on request
You see your diamond before we set it
- 1 You chooseYour setting, carat and gold.
- 2 You see itA video of your exact diamond and its IGI report, within 24 hours.
- 3 We set itApprove it, and we set your ring by hand.
DEF color · VS2+ clarity · IGI certified
Postcards from our couples
Real rings, real people, shared with their permission.







