Choose a ring that fits your finger well.
Measure the internal diameter of the ring in millimeters (mm).
Use the chart to find the closest matching ring size.
Wide rings measure differently due to their fit. If you’re measuring for a wide ring, subtract
0.25–0.50 ring sizes from the measured size for a comfortable fit.
Find Your Ring Size
A&O (US) Size
Internal Diameter (mm)
3.25
3.5
3.75
14.1
14.4
14.7
4.25
4.50
4.75
15.1
15.3
15.5
5.25
5.50
5.75
15.9
16.1
16.3
6.25
6.50
6.75
16.7
16.9
17.1
7.25
7.50
7.75
17.5
17.7
17.9
8.25
8.50
8.75
18.3
18.5
18.7
9.25
9.50
9.75
19.1
19.3
19.5
10.25
10.50
10.75
19.9
20.1
20.3
11.25
11.50
11.75
20.8
21.0
21.2
12.25
12.50
12.75
21.6
21.8
22.0
13.25
13.50
13.75
22.4
22.6
22.8
Take a tape measure, a piece of string, or a strip of paper.
-
Wrap it tightly around the finger where you'll be wearing the ring. It should feel snug to get an
accurate measurement. If you're stacking rings, keep in mind where on your finger the ring will rest,
and mark where the ends meet.
-
Place the string or paper strip on a flat surface and measure the length up to your mark with a ruler.
Refer to the chart above to find the closest match for your ring size.
Find Your Ring Size
A&O (US) Size
Circumference (mm)
3.25
3.5
3.75
44.3
45.2
46.2
4.25
4.50
4.75
47.4
48.1
48.7
5.25
5.50
5.75
50.0
56.0
51.2
6.25
6.50
6.75
52.5
53.1
53.7
7.25
7.50
7.75
55.0
55.6
56.2
8.25
8.50
8.75
57.5
58.1
58.7
9.25
9.50
9.75
60.0
60.6
61.3
10.25
10.50
10.75
62.5
63.1
63.8
11.25
11.50
11.75
65.3
65.9
66.6
12.25
12.50
12.75
67.8
68.5
69.1
13.25
13.50
13.75
70.3
71.0
71.6
