Sizing varies slightly by brand and band width. This chart is a starting point—we include one complimentary resize on eligible rings within 60 days of delivery where noted on the product.
US / CA
UK
EU
India
Japan
Inside Ø (mm)
5
J
49
9
9
15.7
5.5
K
50
10
10
16.1
6
L½
52
11
12
16.5
6.5
M½
54
12
13
16.9
7
N½
55
14
14
17.3
7.5
O½
57
15
15
17.7
8
P½
58
16
16
18.1
8.5
Q½
60
17
18
18.5
9
R½
61
18
20
18.9
9.5
S½
62
19
21
19.4
10
T½
63
20
22
19.8
11
V½
66
22
24
20.7
12
X½
69
24
27
21.7
Cut a thin strip of paper or string about 12 cm long.
Wrap it snugly around the widest part of the finger (often the knuckle).
Mark where the end meets, then lay flat and measure the length in millimetres—this is the inner circumference.
Divide that length by π (≈ 3.14) to approximate the inner diameter and match the closest EU / US column in the chart tab.
Measure at room temperature; fingers swell slightly during the day.
Diagram: snug wrap at knuckle height
Print this page at 100% scale (no “fit to page”). Cut along the dashed line and wrap around your finger—the edge should meet the circumference that feels snug.