Ring Size Guide

Learn how to determine your ring size and how to convert between different ring sizing systems. 

New Zealand uses the same ring size standard as Britain and Australia, which uses alphabetical letters that are sometimes followed by fractions, e.g., H, L and 1/2, R and 3/4, and so on.

There are two ways in which ring size is measured: inner circumference and inner diameter. Inside circumference is the distance around the inner edge of a ring, and inside diameter is the distance across the centre of the ring between its two inner edges:

You can determine your ring size by measuring the inside diameter of a ring you have at home using our printable ring sizer.

Alternatively, you can contact us to request a free ring sizer, shown below, which you can use to measure your finger (please allow 2 to 3 days for delivery).

ring size conversion table

The ring size chart below can be used to obtain the corresponding ring size for a certain inside circumference or diameter or to convert between North American and British/New Zealand ring sizes.

Inside Circumference (mm)	UK, Australia, NZ Ring Size	Inside Diameter (mm)	US & Canada Ring Size
37.5	A	12	1/2
38.3	A 1/2	12.2	3/4
38.9	B	12.4	1
39.6	B 1/2	12.6	1 1/4
40.2	C	12.8	1 1/2
40.8	C 1/2	13	1 3/4
41.5	D	13.2	2
42.1	D 1/2	13.4	2 1/4
42.8	E	13.6	2 1/2
43.5	E 1/2	13.8	2 3/4
44.1	F	14.1	3
44.5	F 1/2	14.2	3 1/8
44.8	F 3/4	14.3	3 1/4
45.1	G	14.4	3 3/8
45.4	G 1/4	14.5	3 1/2
45.7	G 1/2	14.6	3 5/8
46	H	14.7	3 3/4
46.7	H 1/2	14.9	4
47.3	I	15	4 1/4
48	I 1/2	15.3	4 1/2
48.4	J	15.4	4 5/8
48.8	J 1/4	15.5	4 3/4
49.3	J 1/2	15.7	5
49.6	K	15.8	5 1/8
50	K 1/4	15.9	5 1/4
50.3	K 1/2	16	5 3/8
50.6	L	16.1	5 1/2
51.2	L 1/4	16.3	5 3/4
51.6	L 1/2	16.4	5 7/8
51.9	M	16.5	6
52.5	M 1/2	16.7	6 1/4
53.2	N	16.9	6 1/2
53.8	N 1/2	17.1	6 3/4
54.5	O	17.4	7
54.8	O 1/2	17.5	7 1/4
55.8	P	17.8	7 1/2
56.5	P 1/2	18	7 3/4
57.2	Q	18.2	8
57.7	Q 1/2	18.4	8 1/4
58.2	Q 3/4	18.5	8 1/2
58.5	R	18.6	8 5/8
58.7	R 1/4	18.7	8 3/4
59.1	R 1/2	18.8	8 7/8
59.3	R 3/4	18.9	9
60	S	19.1	9 1/8
60.4	S 1/4	19.2	9 1/4
60.7	S 1/2	19.3	9 3/8
61	S 3/4	19.4	9 1/2
61.3	T	19.5	9 5/8
61.6	T 1/4	19.6	9 3/4
62.3	T 1/2	19.8	10
62.9	U	20	10 1/4
63.5	U 1/2	20.2	10 1/2
63.8	V	20.3	10 5/8
64.2	V 1/4	20.4	10 3/4
65	V 1/2	20.7	11
65.2	W	20.8	11 1/8
65.5	W 1/4	20.9	11 1/4
65.8	W 1/2	20.9	11 3/8
66.2	W 3/4	21.1	11 1/2
66.5	X	21.2	11 5/8
66.7	X 1/4	21.2	11 3/4
66.9	X 1/2	21.3	11 7/8
67.5	Y	21.5	12
68.1	Y 1/2	21.7	12 1/4
68.8	Z	21.9	12 1/2
69.4	Z +1/2	22.1	12 3/4
70.2	Z+1	22.3	13
71	Z+1.5	22.6	13 1/2