Quick answer: Cartier’s current ring sizes follow the European system, so the number is the inside circumference in millimetres. A Cartier 52 is about US 6, a 54 is about US 6.75 (usually sold as US 7), a 56 is about US 7.5, and a 58 is about US 8.5. Cartier does not offer half sizes, and for a wide Love ring many guides suggest sizing up.
How Cartier ring sizes work
Cartier sizes are the European (ISO) size: the number is the ring’s inside circumference in millimetres, so a size 52 ring has a 52 mm inside circumference. This is the same standard we cover in our European ring size to US guide, and you can read more about the standard on Wikipedia.
Cartier rings are typically sold in whole sizes, so if you fall between two numbers you have to choose one. Some size charts also list an older Cartier numbering from 01 to 27, in which each number matches an inside circumference in mm (for example, 16 is about 56.5 mm). If your ring or paperwork shows one of those smaller numbers, convert it using the mm value, not the number.
Cartier to US ring size chart
US sizes are the closest match to each circumference, calculated from the standard and rounded. They are estimates: the real fit also depends on band width and shape.
| Cartier / EU size | Inside diameter | Closest US size |
|---|---|---|
| 48 | 15.3 mm | US 4.5 |
| 50 | 15.9 mm | US 5.25 |
| 52 | 16.6 mm | US 6 |
| 54 | 17.2 mm | US 6.75 (sold as 7) |
| 56 | 17.8 mm | US 7.5–7.75 |
| 58 | 18.5 mm | US 8.5 |
| 60 | 19.1 mm | US 9–9.25 |
| 62 | 19.7 mm | US 10 |
| 64 | 20.4 mm | US 10.75–11 |
For UK letters or other countries, see our world ring size conversion chart and UK ring size chart.
Sizing a Cartier Love ring
The classic Love band is wide, and a wide band tends to feel tighter than a narrow ring in the same size, because more of the finger is covered and the ring has to pass the knuckle. Retail size guides suggest allowing extra room:
- Large knuckles: one guide advises ordering half a size above your measured size.
- Between sizes: choose the larger size.
- Wide band: another retailer guide recommends going up one full size, with some movement being normal. These two guides differ, so try the ring on in a boutique if you can.
For the general rule, see our wide band sizing guide.
How to find your Cartier size
- Measure your finger with a printable ring sizer, or measure a ring you own that fits (see how to measure an existing ring).
- Read the inside circumference in mm.
- That number, rounded up to the nearest whole size, is your Cartier size. For a wide band, add one.
- If possible, confirm with Cartier’s own sizer in a boutique before buying.
Comparing Cartier with other brands
Pandora also uses European-style numbering; see our Pandora ring size chart. Other brands may label sizes by diameter or in US sizes, so check what each number means before converting.
Frequently asked questions
What is a Cartier size 52 in US?
About US 6.
What is a Cartier size 54 in US?
About US 6.75, usually sold as a US 7.
What is a Cartier size 56 in US?
Between US 7.5 and 7.75.
Does Cartier make half sizes?
Cartier’s European-style sizes go up in whole numbers (1 mm steps), so if you are between sizes you choose one.
Should I size up for a Love ring?
Often yes, since the band is wide. Guides suggest from half a size to one full size, so try it on if you can.
Are Cartier sizes the same for men and women?
Yes. The same size scale is used; only the fit preference differs.
