Ring Size Guide
How to measure your ring size
Because it is a ring meant to last a lifetime, choose the right size.
Ring size is an important element that determines both comfort and beauty.
In this guide, from an easy way to measure at home to professional measurement,
we help you find the one piece that fits you perfectly.
The basics of ring size
Ring size is expressed in gō, determined by the inner circumference of the finger. In Japan, sizes 1 to 30 are common. Women often fall in the size 7 to 16 range, and men in the size 13 to 21 range.
How to measure your size
At ANNA DIAMOND we select on a basis ofWe offer a free ring gauge loanYou can slip an actual sized ring onto your finger to check, which is the most accurate way to measure.
Apply for a free ring gauge loan →
Measuring with a paper strip
Use a thread that does not stretch, such as cotton thread or dental floss. The trick is not to pull it tight, but to lay it gently along the finger. Measuring two or three times and taking the average gives an accurate result.
Measuring with a ring you own
Choose a ring that fits perfectly. A wide ring can feel slightly larger than the usual size. If using a ruler is difficult, tracing the inside of the ring on paper to measure the diameter is accurate.
We measure ring sizes at our flagship store in Daikanyama as well. We also send a ring gauge free of charge, so you can take your time trying it at home.
Learn more →
Size conversion chart
| Japan (gō) | Inner circumference (mm) | Inner diameter (mm) | US | EU | UK |
|---|---|---|---|---|---|
| 5 | 45.2 | 14.4 | 3 | 45 | F |
| 6 | 46.1 | 14.7 | 3.5 | 46 | G |
| 7 | 47.1 | 15.0 | 4 | 47 | H |
| 8 | 48.2 | 15.4 | 4.5 | 48 | I |
| 9 | 49.2 | 15.7 | 5 | 49 | J |
| 10 | 50.3 | 16.0 | 5.5 | 50 | K |
| 11 | 51.3 | 16.3 | 6 | 51 | L |
| 12 | 52.4 | 16.7 | 6.5 | 52 | M |
| 13 | 53.4 | 17.0 | 7 | 53 | N |
| 14 | 54.5 | 17.3 | 7 | 54 | O |
| 15 | 55.5 | 17.7 | 7.5 | 55 | P |
| 16 | 56.5 | 18.0 | 8 | 56 | P.5 |
| 17 | 57.5 | 18.3 | 8 | 57 | Q |
| 18 | 58.6 | 18.6 | 8.5 | 58 | R |
| 19 | 59.6 | 19.0 | 9 | 59 | S |
| 20 | 60.6 | 19.3 | 9.5 | 60 | T |
Note: highlighted rows are size ranges common among women. Overseas sizes are approximate.
Size differences between fingers
Even on the same hand, size differs from finger to finger. It is also common to see a difference of about 0.5 to 1 gō between the left and right hands. If you know which finger it is for, be sure to measure that finger.
The dominant hand is often about 0.5 to 1 gō larger. If you know which finger it is for, be sure to measure that finger. It is not unusual for the sizes to differ between left and right.
Points for measuring accurately
When your body temperature is stable
Fingers change in thickness throughout the day. Afternoon to early evening is the most stable.
Measure two or three times and take the average
Measuring several times across different days gives a more accurate size.
If your knuckle is thicker
Choose a size that passes over the knuckle. A little extra room at the base is no problem.
Differences by ring width
A wide ring feels tighter. For a width of 4mm or more, 0.5 to 1 gō larger is comfortable.
Afternoon to early evening, when you are feeling settledis what we recommend. Avoid measuring right after exercise or drinking, as fingers tend to swell then. If you can, measure several times over two or three days and take the average for peace of mind.
About size adjustment
With changes in body shape or the seasons, a ring may no longer fit. At ANNA DIAMOND,within one year of purchase, we offer free size adjustment of up to ±1 to 2 gōof charge.
See aftercare details →
Possible for nearly all designs. No effect on the finish.
Possible for many designs. Depends on the design, so please confirm.
Please consult us. We may recommend a new piece in some cases.
Size adjustment is not a cure for everything. A large change in size can affect a ring's strength and design. If your size changes temporarily, as with pregnancy and childbirth, we sometimes recommend waiting until your body shape settles. We advise with the lifespan of the ring as our first priority.
Frequently Asked Questions
Ring size is an important element for balancing comfort and beauty.
If you are unsure, feel free to consult us.
ANNA DIAMONDwill help you find the one piece that fits you perfectly.
Contact
If you are unsure about size, feel free to consult us. We are here for you by email, LINE, online consultation, or at our flagship store in Daikanyama.