BRAND GUIDE
Tiffany & Co. ring size guide
Tiffany follows standard US sizing
Unlike Cartier's house scale, Tiffany's ring sizes track the general US numbering system directly, so a Tiffany US 6 is a standard US 6 elsewhere. Quarter sizes exist but are typically only fitted in a boutique, online ordering is usually limited to half sizes.
Conversion chart
Compare against the full ring size chart for India, Japan, and China equivalents.
| US size | EU size | UK size | Diameter (mm) |
|---|---|---|---|
| 4.5 | 47.5 | I 1/2 | 15.3 |
| 5 | 49 | J 1/2 | 15.7 |
| 5.5 | 50.5 | K 1/2 | 16.1 |
| 6 | 51.5 | L 1/2 | 16.5 |
| 6.5 | 53 | M 1/2 | 16.9 |
| 7 | 54.5 | N 1/2 | 17.3 |
| 7.5 | 55.5 | O 1/2 | 17.7 |
| 8 | 57 | P 1/2 | 18.1 |
| 9 | 59.5 | R 1/2 | 18.9 |
The Setting and thin pavé bands run differently
Tiffany's signature thin, delicate bands, including pavé eternity styles, tend to feel tighter than a plain band at the same nominal size, similar to what happens with any narrow band that sits close to the finger without much surface area to distribute pressure. If you've worn a thicker Tiffany band comfortably before, don't assume the same number in a thin pavé style will feel identical.
Resizing an engagement ring
Tiffany typically resizes solitaire engagement rings within about two sizes of the original, and offers this service directly rather than through a third-party jeweler, which keeps the setting and prong work to their own standard. Eternity bands and rings with stones set into the shank have much less room to resize, sometimes none at all, since stretching or compressing the metal risks loosening the stones.