Ring Sizing Chart

Aus Size	US Size	Internal diameter	Internal circumference
F 1/2	3	14.3mm	44.8mm
G	3 1/4	14.5mm	45.5mm
G 1/2	3 1/2	14.7mm	46.1mm
H	3 3/4	14.9mm	46.7mm
H 1/2	4	15.1mm	47.4mm
I	4 1/4	15.3mm	48.0mm
I 1/2	4 1/2	15.3mm	48.3mm
J	4 3/4	15.4mm	48.7mm
J 1/4	4 7/8	15.6mm	49.0mm
J 1/2	5	15.7mm	49.3mm
K	5 1/4	15.9mm	50.0mm
K 1/4	5 3/8	16.0mm	50.3mm
K 1/2	5 1/2	16.1mm	50.6mm
L	5 3/4	16.3mm	51.2mm
L 1/4	5 7/8	16.4mm	51.6mm
L 1/2	6	16.5mm	51.9mm
M	6 1/4	16.7mm	52.5mm
M 1/2	6 1/2	16.9mm	53.2mm
N	6 3/4	17.1mm	53.8mm
N 1/2	7	17.3mm	54.4mm
O	7 1/4	17.5mm	55.1mm
O 1/2	7 1/2	17.7mm	55.7mm
P	7 3/4	17.9mm	56.3mm
P 1/2	8	18.1mm	57.0mm
Q	8 1/4	18.3mm	57.6mm
Q 1/2	8 1/2	18.5mm	58.2mm
R	8 3/4	18.8mm	58.9mm
R 1/2	9	19.0mm	59.5mm
S	9 1/4	19.2mm	60.2mm
S 1/2	9 1/2	19.4mm	60.8mm
T	9 3/4	19.6mm	61.4mm
T 1/2	10	19.8mm	62.1mm
U	10 1/4	20.0mm	62.7mm
U 1/2	10 1/2	20.2mm	63.4mm
V	10 5/8	20.4mm	64.0mm
V 1/2	11	20.7mm	65.0mm
W	11 1/8	20.8mm	65.3mm
W 1/2	11 3/8	21.0mm	65.9mm
X	11 5/8	21.2mm	66.5mm
X 1/2	12	21.5mm	67.5mm
Y	12 1/4	21.6mm	67.8mm
Y 1/2	12 3/8	21.7mm	68.1mm
Z	12 1/2	21.8mm	68.5mm