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.
Shown: our 6mm Colombian emerald band
Emerald, all the way round
A line of green,
unbroken.
Each emerald is chosen to sit beside the next, matched in tone so the row reads as one continuous line of color, then set by hand in solid gold.
Build your stack
Wear it three ways.
-
Engagement ringThe Marlowe
From $1,850 →
-
Wedding bandThe Vine Twist
From $850 →
-
Your bandColombian Emerald & Diamond Eternity Vintage Band
Choose your metal →
The Marlowe echoes the milgrain while a 1.8mm wedding band keeps the stack balanced.
Styling preview · engagement ring shown at 2ct
Watch how your band is made.
Every band is cast, shaped, set and polished by hand in our family studio. These are the stages yours passes through before it reaches your door.
Grinding the Band
Once your band is cast in its rough form, every surface is ground down by hand to reveal its true shape and width: the same patient first step behind every ring that leaves our workshop.
Setting by Hand
Stones and Stone Inlay® are set one at a time, the metal worked around each by hand until it sits flush and secure. It's the slow part, and the part we never rush.
Hand Polished
Every surface is polished inside and out through progressively finer abrasives, until the band feels smooth against the skin and catches the light evenly.
The Finished Band
Checked for polish, comfort and every setting before it leaves the workshop, then shipped to you fully insured.
Before you choose
Questions, answered.
Still wondering about something? Write to our family studio and Jack will answer personally. Ask us
