Ring size explanation – diameter & circumference

In Europe, ring sizes are indicated based on the inner circumference of the ring in millimeters . This means that a size 54 corresponds to an inner circle of 54 mm.

The diameter is the distance from edge to edge inside the ring and is directly related to the circumference:

• Circumference (mm) = the total length around the inside of the ring.
• Diameter (mm) = the width of the ring opening from left to right.

Example:

• A ring size 54 has a circumference of 54 mm and a diameter of approximately 17.2 mm .

Still unsure? Simply measure using our size guide in the PDF , or take an existing ring and compare it to the table.

👉 [Download the ring size PDF]