Ring Size Conversion: Don't Ruin the Surprise

Buying a ring online for a partner in another country? Ring sizing systems are completely different.

The Systems

• US/Canada: Numerical scale (e.g., Size 6, 7, 8).
• UK/Australia: Alphabetical scale (e.g., Size L, M, N).
• Europe: Numerical based on circumference in mm (e.g., Size 52, 54).

How to Measure

The safest way is to measure the inside diameter of a ring that already fits well in millimeters. A US Size 7 has a diameter of roughly 17.3mm. A UK Size N is also roughly 17.3mm. This measurement is universal regardless of the sizing scale used by the jeweler.