Ring size reference

Ring Size Conversion Chart.

Compare India, US, UK and EU ring sizes using the inside diameter of a ring you already own.

Find the closest measurement

India, US, UK and EU sizes

Measure the inner diameter across the widest part of your ring, then find the nearest millimeter value below. The circumference is the distance around the inside edge.

Ring size conversion chart for India, US, UK and EU sizes, with inner diameter and circumference in millimeters
Inner diameter	Circumference	India	US	UK	EU
13.1 mm	41.2 mm	1	3	F½	41
13.3 mm	41.8 mm	2	3	F½	42
13.7 mm	43.0 mm	3	3	F½	43
13.9 mm	43.7 mm	4	3	F½	44
14.3 mm	44.9 mm	5	3½	G	45
14.7 mm	46.2 mm	6	3½	H	46
15.1 mm	47.4 mm	7	4	I	47
15.3 mm	48.1 mm	8	4½	I½	48
15.5 mm	48.7 mm	9	4½	J	49
15.9 mm	50.0 mm	10	5	K	50
16.3 mm	51.2 mm	11	5½	L	51
16.5 mm	51.8 mm	12	6	L½	52
16.9 mm	53.1 mm	13	6½	M½	53
17.3 mm	54.3 mm	14	7	N½	54
17.5 mm	55.0 mm	15	7	O	55
17.9 mm	56.2 mm	16	7½	P	56
18.1 mm	56.9 mm	17	8	P½	57
18.5 mm	58.1 mm	18	8½	Q½	58
18.8 mm	59.1 mm	19	9	R	59
19.2 mm	60.3 mm	20	9	S	60
19.4 mm	60.9 mm	21	9½	S½	61
19.8 mm	62.2 mm	22	10	T½	62
20.0 mm	62.8 mm	23	10	U	63
20.4 mm	64.1 mm	24	10½	V	64
20.6 mm	64.7 mm	25	11	V½	65
21.0 mm	66.0 mm	26	11½	W½	66
21.1 mm	66.3 mm	27	11½	X	66
21.6 mm	67.9 mm	28	12½	Y	68
22.0 mm	69.1 mm	29	12½	Z½	69
22.3 mm	70.1 mm	30	13	Z+1	70

Sizes are approximate conversions. Different jewelers may use slightly different charts; compare your millimeter measurement with the seller’s chart before purchasing.

How to use the chart

Start with millimeters.

Diameter and circumference

Inner diameter is the straight-line distance across the opening of a ring. Inner circumference is the distance around that opening. You can calculate circumference by multiplying diameter by π (about 3.1416).

Regional size labels

US sizes use numbers and half sizes; UK sizes use letters. EU sizes are approximately the inner circumference in millimeters. The India column follows the Indian size scale used by this site’s measurement tool.

Between two rows?

Use the nearest diameter as a starting point, then check the jeweler’s size chart and return policy. A wide band can feel tighter than a narrow band with the same inner diameter.

Need your measurement?

Find your size with a ring you own.

Calibrate your screen, align the ring’s inner edge and see your closest size in all four systems.

Open the ring sizer