The World of Jewellery

Practical guides to choosing jewellery, materials and care — so you know what you are buying and how to wear it.

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Materials and qualityMedical gold – what it is and how to care for itWhat medical gold is, how it differs from solid gold and why it doesn't cause allergies – plus its benefits, care tips and pieces with 18K gold plating.

Size guide

How to measure your finger

Measure a ring you already have

Take a ring that fits the finger you want to wear it on. Use a ruler to measure straight across the inside — that is the inner diameter in millimetres, and it is also the ROTAS69 size. Enter it in the calculator.

Measure your finger

Wrap a narrow strip of paper around the base of your finger (not over the knuckle). Mark where it overlaps, straighten it and measure the length in millimetres — that is the circumference.

Size chart

ROTAS69 Inner Ø	US	EU	UK	Circumference
14.5 mm	3.5	46	G	45.6 mm
14.9 mm	4	47	H	46.8 mm
15.3 mm	4.5	48	I	48.1 mm
15.7 mm	5	49	J	49.3 mm
16.1 mm	5.5	51	K	50.6 mm
16.5 mm	6	52	L	51.8 mm
16.9 mm	6.5	53	M	53.1 mm
17.3 mm	7	54	N	54.4 mm
17.7 mm	7.5	56	O	55.6 mm
18.1 mm	8	57	P	56.9 mm
18.5 mm	8.5	58	Q	58.1 mm
18.9 mm	9	59	R	59.4 mm
19.4 mm	9.5	61	S	60.9 mm
19.8 mm	10	62	T	62.2 mm
20.2 mm	10.5	63	U	63.5 mm
20.6 mm	11	65	V	64.7 mm
21.0 mm	11.5	66	W	66.0 mm
21.4 mm	12	67	X	67.2 mm
21.8 mm	12.5	68	Y	68.5 mm
22.2 mm	13	70	Z	69.7 mm
22.6 mm	13.5	71	Z+1	71.0 mm
23.0 mm	14	72	Z+2	72.3 mm
23.4 mm	14.5	74	Z+3	73.5 mm
23.8 mm	15	75	Z+4	74.8 mm

Full size chart — exact values. The ROTAS69 size is the inner diameter of the ring (Inner Ø) in millimetres. The EU size corresponds to the circumference; UK letters may differ by ±½ between jewellers.