To determine the correct ring size please refer to the table below with ring size measurements as well as a online chart

 Ring Size (UK)     Measurement (mm)
A           37.50
B           38.75
C           40.00
D           41.25
E           42.50
F           43.75
G           45.00
H          46.25
I            47.50
J            48.75
K          50.00
L           51.25
M          52.50
N          53.75
O          55.00
P           56.25
Q          57.50
R           58.75
S           60.00
T           61.25
U          62.50
V          63.75
W         65.00
X          66.25
Y          67.50
Z           88.75