There are several different ways of determining your ring size in standard US sizing.

If you already know your ring size in EU or other international measurement, find out what your size converts to in standard US sizing using the chart below.

To find out your ring size at home, you could use a piece of string or dental floss, wrap it around the base of the finger to measure the diameter. If you are between sizes, the safest option would be to order up. Please make sure you do not wrap the string too tightly and consider the size of your knuckles, which are often the largest part of your finger.

Please keep in mind that the same finger on the opposite hand may have a different ring size, and measure your finger at the end of the day when it is likely to be the largest.
You could also determine your ring size by measuring the inner diameter of a ring you already own and fits the finger on which you would like to wear the new ring. This method comes in handy when you are buying a ring for your loved one and do not want ruin the surprise.

 

Inside Diameter Inside Circumference Sizes
MM Inches MM Inches British & Australian US & Canada French & Russian German Japanese Swiss
9.91 0.390 31.13 1.22 0
10.72 0.442 33.68 1.39 0
11.53 0.454 36.22 1.43 0
11.95 0.474 37.54 1.49 A
12.18 0.482 38.26 1.51 A 1/2
12.37 0.487 38.86 1.53 B 1 1
12.60 0.496 39.58 1.56 B 1/2 1 1/4
12.78 0.503 40.15 1.58 C 1 1/2
13.00 0.512 40.84 1.61 C 1/2 1 3/4
13.21 0.520 41.50 1.63 D 2 41 1/2 13 1/2 2 1 1/2
13.41 0.528 42.13 1.66 D 1/2 2 1/4
13.61 0.536 42.76 1.68 E 2 1/2 42 3/4 13 3/4 3 2 3/4
13.83 0.544 43.45 1.71 E 1/2 2 3/4
14.05 0.553 44.14 1.74 F 3 44 14 4 4
14.15 0.557 44.45 1.75 F 1/2 3 1/8
14.25 0.561 44.77 1.76 F 3/4 3 1/4
14.36 0.565 45.11 1.77 G 3 3/8 45 1/4 5 5 1/4
14.45 0.569 45.40 1.79 G 1/4 3 1/2 14 1/2
14.56 0.573 45.74 1.80 G 1/2 3 5/8 6
14.65 0.577 46.02 1.81 H 3 3/4 46 1/2 6 1/2
14.86 0.585 46.68 1.84 H 1/2 4 15 7
15.04 0.592 47.25 1.86 I 4 1/4 47 3/4 7 3/4
15.27 0.601 47.97 1.89 I 1/2 4 1/2 15 1/4 8
15.40 0.606 48.38 1.90 J 4 5/8 49 15 1/2 9
15.53 0.611 48.79 1.92 J 1/4 4 3/4
15.70 0.618 49.32 1.94 J 1/2 5 15 3/4 9
15.80 0.622 49.64 1.95 K 5 1/8 50 10
15.90 0.626 49.95 1.97 K 1/4 5 1/4
16.00 0.630 50.27 1.98 K 1/2 5 3/8 10
16.10 0.634 50.58 1.99 L 5 1/2 51 3/4 16 11 3/4
16.30 0.642 51.21 2.02 L 1/4 5 3/4
16.41 0.646 51.55 2.03 L 1/2 5 7/8
16.51 0.650 51.87 2.04 M 6 52 3/4 16 1/2 12 12 3/4
16.71 0.658 52.50 2.07 M 1/2 6 1/4
16.92 0.666 53.16 2.09 N 6 1/2 54 17 13 14
17.13 0.674 53.82 2.12 N 1/2 6 3/4
17.35 0.683 54.51 2.15 O 7 55 1/4 17 1/4 14 15 1/4
17.45 0.687 54.82 2.16 O 1/2 7 1/4
17.75 0.699 55.76 2.20 P 7 1/2 56 1/2 17 3/4 15 16 1/2
17.97 0.707 56.45 2.22 P 1/2 7 3/4
18.19 0.716 57.15 2.25 Q 8 57 3/4 18 16 17 3/4
18.35 0.722 57.65 2.27 Q 1/2 8 1/4
18.53 0.729 58.21 2.29 Q 3/4 8 1/2 18 1/2 17
18.61 0.733 58.47 2.30 R 8 5/8 59 19
18.69 0.736 58.72 2.31 R 1/4 8 3/4
18.80 0.740 59.06 2.32 R 1/2 8 7/8
18.89 0.748 59.34 2.35 R 3/4 9 19 18
19.10 0.752 60.00 2.36 S 9 1/8 60 1/4 20 1/4
19.22 0.757 60.38 2.38 S 1/4 9 1/4
19.31 0.760 60.66 2.39 S 1/2 9 3/8
19.41 0.764 60.98 2.40 S 3/4 9 1/2 19 1/2 19
19.51 0.768 61.29 2.41 T 9 5/8 61 1/2 21 1/2
19.62 0.772 61.64 2.43 T 1/4 9 3/4
19.84 0.781 62.33 2.45 T 1/2 10 20 20
20.02 0.788 62.89 2.48 U 10 1/4 62 3/4 21 22 3/4
20.20 0.797 63.46 2.50 U 1/2 10 1/2 20 1/4 22
20.32 0.800 63.84 2.51 V 10 5/8 63 23 3/4
20.44 0.805 64.21 2.53 V 1/4 10 3/4
20.68 0.814 64.97 2.56 V 1/2 11 20 3/4 23
20.76 0.817 65.22 2.57 W 11 1/8 65 25
20.85 0.821 65.50 2.58 W 1/4 11 1/4
20.94 0.824 65.78 2.59 W 1/2 11 3/8
21.08 0.830 66.22 2.61 W 3/4 11 1/2 21 24
21.18 0.834 66.54 2.62 X 11 5/8 66 1/4 26 1/4
21.24 0.836 66.73 2.63 X 1/4 11 3/4
21.30 0.839 66.92 2.64 X 1/2 11 7/8
21.49 0.846 67.51 2.66 Y 12 67 1/2 21 1/4 25 27 1/2
21.69 0.854 68.14 2.68 Y 1/2 12 1/4
21.89 0.862 68.77 2.71 Z 12 1/2 68 3/4 21 3/4 26 28 3/4
22.10 0.870 69.43 2.73 Z +1/2 12 3/4
22.33 0.879 70.15 2.76 Z+1 13 22 27
22.60 0.890 71.00 2.80 Z+1.5 13.5