Ring Size Chart

NFC Ring Size*	Inside Diameter (inches)	Inside Diameter (mm)	Inside Circumference (inches)	Inside Circumference (mm)	British	Japanese	Swiss
4 1/2	0.602	15.3	1.89	48	I	8
4 3/4	0.61	15.5	1.915	48.7	J		9
5	0.618	15.7	1.941	49.3	J 1/2	9
5 1/4	0.626	15.9	1.966	49.9	K		10
5 1/2	0.634	16.1	1.991	50.6	K 1/2	10
5 3/4	0.642	16.3	2.016	51.2	L		11.75
6	0.65	16.5	2.041	51.8	L 1/2	11	12.75
6 1/4	0.658	16.7	2.066	52.5	M	12
6 1/2	0.666	16.9	2.091	53.1	M 1/2	13	14
6 3/4	0.674	17.1	2.116	53.8	N
7	0.682	17.3	2.141	54.4	N 1/2	14	15.25
7 1/4	0.69	17.5	2.167	55	O
7 1/2	0.698	17.7	2.192	55.7	O 1/2	15	16.5
7 3/4	0.706	17.9	2.217	56.3	P
8	0.714	18.1	2.242	56.9	P 1/2	16	17.75
8 1/4	0.722	18.3	2.267	57.6	Q
8 1/2	0.73	18.5	2.292	58.2	Q 1/2	17
8 3/4	0.738	18.7	2.317	58.9	R		19
9	0.746	18.9	2.342	59.5	R 1/2	18
9 1/4	0.754	19.2	2.368	60.1	S		20.25
9 1/2	0.762	19.4	2.393	60.8	S 1/2	19
9 3/4	0.77	19.6	2.418	61.4	T		21.5
10	0.778	19.8	2.443	62.1	T 1/2	20
10 1/4	0.786	20	2.468	62.7	U	21
10 1/2	0.794	20.2	2.493	63.3	U 1/2	22	22.75
10 3/4	0.802	20.4	2.518	64	V
11	0.81	20.6	2.543	64.6	V 1/2	23
11 1/4	0.818	20.8	2.569	65.2	W		25
11 1/2	0.826	21	2.594	65.9	W 1/2	24
11 3/4	0.834	21.2	2.619	66.5	X
12	0.842	21.4	2.644	67.2	X 1/2	25	27.5
12 1/4	0.85	21.6	2.669	67.8	Y
12 1/2	0.858	21.8	2.694	68.4	Z	26	28.75
12 3/4	0.866	22	2.719	69.1	Z 1/2
13	0.874	22.2	2.744	69.7		27
13 1/4	0.882	22.4	2.769	70.3	Z1
13 1/2	0.89	22.6	2.795	71
13 3/4	0.898	22.8	2.82	71.6	Z2
14	0.906	23	2.845	72.3	Z3
14 1/4	0.914	23.2	2.87	72.9
14 1/2	0.922	23.4	2.895	73.5	Z4
14 3/4	0.93	23.6	2.92	74.2
15	0.938	23.8	2.945	74.8
15 1/4	0.946	24	2.97	75.4
15 1/2	0.954	24.2	2.996	76.1
15 3/4	0.962	24.4	3.021	76.7
16	0.97	24.6	3.046	77.4

* Our engineers told us to let you know NFC Ring sizes are subject to a tolerance of +/- 0.2mm.
In normal language, this means that due to the polishing process, NFC Ring you receive could be exactly as the quoted size, or around 2 average human hairs larger or smaller. Which is a tiny possible variance, but we thought we should let you know.