Cartier ring size guide

Cartier uses European (ISO) sizing — the number is the inner circumference in millimetres. A Cartier 52 is a 52 mm circumference, i.e. a US 6.

EU sizing system

54 starter value

2026-06-24 source review

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I know my size in Value

Your size is US 7 (UK N½, EU 54).

Fit confidence Exact table match

Fit confidence 76/100 · Medium EU/ISO size is based on inner circumference in millimetres. Confirm the fit style with the brand, especially for wide or rigid bands.

17.32 mm Circ mm 54.4 mm

US: 7
UK: N½
EU / ISO: 54
Japan: 14
CH / IT / ES: 14
Inner diameter, millimetres: 17.32
Circ mm: 54.4

Why this size?

Your input maps to US 7 — UK N½, EU 54, JP 14, Ø 17.32 mm.

Inner diameter is exact to about ±0.1 mm. String or on-screen methods add roughly ½–1 size of noise, so confirm with a second method before buying an expensive or non-resizable ring.

Open US 7 size guide

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Ring fit fix advisor

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Converter chart
US	UK	EU	JP	CH	Inner diameter, millimetres	Circ mm
3	F½	44	4	4	14.07	44.2
3.5	G½	45	5	5	14.48	45.5
4	H½	47	7	7	14.88	46.8
4.5	I½	48	8	8	15.29	48.0
5	J½	49	9	9	15.70	49.3
5.5	K½	51	10	11	16.10	50.6
6	L½	52	12	12	16.51	51.9
6.5	M½	53	13	13	16.92	53.1
7	N½	54	14	14	17.32	54.4
7.5	O½	56	15	16	17.73	55.7
8	P½	57	16	17	18.14	57.0
8.5	Q½	58	17	18	18.54	58.3
9	R½	60	18	20	18.95	59.5
9.5	S½	61	19	21	19.35	60.8
10	T½	62	20	22	19.76	62.1
10.5	U½	63	22	23	20.17	63.4
11	V½	65	23	25	20.57	64.6
11.5	W½	66	24	26	20.98	65.9
12	Y	67	25	27	21.39	67.2
12.5	Z	68	26	28	21.79	68.5
13	Z½	70	27	30	22.20	69.7

How Cartier sizing works

Cartier rings (including the Love and Trinity) are sized in EU/ISO numbers, usually 48–62. Cartier 50 ≈ US 5½, 52 ≈ US 6, 54 ≈ US 7, 56 ≈ US 7½.

Fast conversion anchors

These common reference points come from the same table used by the converter.

Fast conversion anchors
Brand size	US	UK	Diameter
52	6	L½	16.51 mm
54	7	N½	17.32 mm
58	8.5	Q½	18.54 mm

Wide-band size calculator

Estimate the order size for a wider band, then confirm before buying a non-resizable ring.

Normal US size Band width: 6 mm Fit preference Knuckle shape

Cartier exact-size answers

Cartier ring size chart

Cartier ring size chart
Cartier (EU)	US	UK	Inner diameter, millimetres
44	3	F½	14.07
45	3.5	G½	14.48
47	4	H½	14.88
48	4.5	I½	15.29
49	5	J½	15.70
51	5.5	K½	16.10
52	6	L½	16.51
53	6.5	M½	16.92
54	7	N½	17.32
56	7.5	O½	17.73
57	8	P½	18.14
58	8.5	Q½	18.54
60	9	R½	18.95
61	9.5	S½	19.35
62	10	T½	19.76
63	10.5	U½	20.17
65	11	V½	20.57
66	11.5	W½	20.98
67	12	Y	21.39
68	12.5	Z	21.79
70	13	Z½	22.20

Frequently asked questions

What is Cartier ring size 52 in US?

Cartier 52 is a US 6 (UK L½, 52 mm circumference, 16.5 mm diameter). Cartier uses EU/ISO sizing.

What is a Cartier Love ring size 54 in US?

Cartier 54 is a US 7 (UK N½, 54 mm circumference). The Love bracelet and rings both use the EU number = circumference in mm.

Does Cartier use US ring sizes?

No. Cartier uses the European (ISO 8653) system, where the size equals the inner circumference in millimetres. Convert to US with the tool above.

Ringsizely is an independent ring size converter and is not affiliated with, endorsed by, or sponsored by Cartier. Brand names are used for identification only. Always confirm with the retailer before ordering a non-resizable ring.