Ring Sizing

UK		USA		Circumference(mm)	Diameter(mm)
A				37.7	12.00
A1/2				38.33	12.20
B				38.96	12.40
B1/2		0.75		39.58	12.60
C		1.25		40.53	12.90
C1/2		1.50		41.15	13.10
D		1.75		41.78	13.30
D1/2		2.00		42.41	13.50
E		2.25		43.04	13.70
E1/2		2.50		43.67	13.90
F		2.75		44.30	14.10
F1/2		3.00		44.92	14.30
G		3.25		45.55	14.50
G1/2		3.50		46.18	14.70
H		3.75		46.81	14.90
H1/2		4.00		47.44	15.10
I		4.25		48.07	15.30
I1/2		4.50		48.69	15.50
J		4.75		49.32	15.70
J1/2		5		49.95	15.90
K		5.25		50.58	16.10
K1/2		5.50		51.21	16.30
L		5.75		51.84	16.50
L1/2		6.00		52.46	16.70
M		6.25		53.09	16.90
M1/2		6.50		53.72	17.10
N		6.75		54.35	17.30
N1/2		7.00		54.98	17.50
O		7.25		55.61	17.70
P		7.75		56.86	18.10
P1/2		8.00		57.49	18.30
Q		8.25		58.12	18.50
Q1/2		8.50		58.75	18.70
R		8.75		59.38	18.90
R1/2		9.00		60.00	19.10
S		9.25		60.63	19.30
S1/2		9.50		61.26	19.50
T		9.75		61.89	19.70
T1/2		10.00		62.52	19.9
U		10.50		63.15	20.10
U1/2		10.50		63.77	20.30
V		10.75		64.40	20.50
V1/2		11.00		65.03	20.70
W1/2		11.50		66.29	21.10
X		11.75		66.92	21.30
X1/2		12.00		67.54	21.50
Y		12.25		68.17	21.70
Y1/2		12.50		68.80	21.90
Z		12.75		69.43	22.10
Z1/2		13.00		70.06	22.30