Nina's Jewellery Sizing Guide
In Australia rings are measured on an alphabetical scale including half sizes. The same scale is used in Ireland and the United Kingdom.
ring size conversion
Finger circumference
37.54 38.26 38.86 39.58 40.15 40.84 41.50 42.13 42.76 43.45 44.14 44.45 45.11 45.74 46.02 46.68 47.25 47.97 48.38 49.32 49.64 50.27 50.58 51.55 51.87 52.50 53.16 53.82 54.51 54.82 55.76 56.45 57.15 57.65 58.47 59.06 60.00 60.66 61.29 62.33 62.89 63.46 63.84 64.97 65.22 65.78 66.54 66.92 67.51 68.14 68.77 69.43 70.15
Diameter (inside of ring)
11.95 12.18 12.37 12.60 12.78 13.00 13.21 13.41 13.61 13.83 14.05 14.15 14.36 14.56 14.65 14.86 15.04 15.27 15.40 15.70 15.80 16.00 16.10 16.41 16.51 16.71 16.92 17.13 17.35 17.45 17.75 17.97 18.19 18.35 18.61 18.80 19.10 19.31 19.51 19.84 20.02 20.20 20.32 20.68 20.76 20.94 21.18 21.30 21.49 21.69 21.89 22.10 22.33
USA ring size
1/2 3/4 1 1 1/4 1 1/2 1 3/4 2 2 1/4 2 2/4 2 3/4 3 3 1/8 3 3/8 3 5/8 3 3/4 4 4 1/4 4 1/2 4 5/8 5 5 1/8 5 3/8 5 1/2 5 7/8 6 6 1/4 6 1/2 6 3/4 7 7 1/4 7 1/2 7 3/4 8 8 1/4 8 5/8 8 7/8 9 1/8 9 3/8 9 5/8 10 10 1/4 10 1/2 10 5/8 11 11 1/8 11 3/8 11 5/8 11 7/8 12 12 1/4 12 1/2 12 3/4 13
British ring size
A A 1/2 B B 1/2 C C 1/2 D D 1/2 E E 1/2 F F 1/2 G G 1/2 H H 1/2 I I 1/2 J J 1/2 K K 1/2 L L 1/2 M M 1/2 N N 1/2 O O 1/2 P P 1/2 Q Q 1/2 R R 1/2 S S 1/2 T T 1/2 U U 1/2 V V 1/2 W W 1/2 X X 1/2 Y Y 1/2 Z Z 1/2 Z+1
