Cut a piece of paper with the width of +/- 5mm (0.19685"). Make sure it is long enough to wrap around your finger with some extra length to spare. Wrap the piece of paper around the intended finger. Make sure it is not wrapped too tight or loose and make a mark across the paper where it meets. Measure the length by ruler and compare with the inside circumference measurement (mm/inch) on the ring size chart below.
1. Cut Paper Template
2. Measure Your Finger
3. Match Your Size
US
SizeUK/SA
SizeInside
DiameterInside
Circumference
3 1/2 US
G
14.5mm (0.570")
45.5mm (1.790")
3 3/4 US
G 1/2
14.7mm (0.578")
46.1mm (1.815")
4 US
H
14.9mm (0.586")
46.7mm (1.840")
4 1/4 US
H 1/2
15.1mm (0.594")
47.4mm (1.865")
4 1/2 US
I
15.3mm (0.602")
48.0mm (1.890")
4 3/4 US
J
15.5mm (0.610")
48.7mm (1.915")
5 US
J 1/2
15.7mm (0.618")
49.3mm (1.941")
5 1/4 US
K
15.9mm (0.626")
49.9mm (1.966")
5 1/2 US
K 1/2
16.1mm (0.634")
50.6mm (1.991")
5 3/4 US
L
16.3mm (0.642")
51.2mm (2.016")
6 US
L 1/2
16.5mm (0.650")
51.8mm (2.041")
6 1/4 US
M
16.7mm (0.658")
52.5mm (2.066")
6 1/2 US
M 1/2
16.9mm (0.666")
53.1mm (2.091")
6 3/4 US
N
17.1mm (0.674")
53.8mm (2.116")
7 US
N 1/2
17.3mm (0.682")
54.4mm (2.141")
7 1/4 US
O
17.5mm (0.690")
55.0mm (2.167")
7 1/2 US
O 1/2
17.7mm (0.698")
55.7mm (2.192")
7 3/4 US
P
17.9mm (0.706")
56.3mm (2.217")
8 US
P 1/2
18.1mm (0.714")
56.9mm (2.242")
8 1/4 US
Q
18.3mm (0.722")
57.6mm (2.267")
8 1/2 US
Q 1/2
18.5mm (0.730")
58.2mm (2.292")
8 3/4 US
R
18.7mm (0.738")
58.9mm (2.317")
9 US
R 1/2
18.9mm (0.746")
59.5mm (2.342")
9 1/4 US
S
19.2mm (0.754")
60.1mm (2.368")
9 1/2 US
S 1/2
19.4mm (0.762")
60.8mm (2.393")
9 3/4 US
T
19.6mm (0.770")
61.4mm (2.418")
10 US
T 1/2
19.8mm (0.778")
62.1mm (2.443")