Our rings come in different sizes:

Taille/Maat/Size (EU)Diamètre/Diameter/Diameter
5016,0 mm
5216,6 mm
5417,3 mm
5618,0 mm
5818,5 mm
6019,3 mm
Take a ring that fits your finger. Put the ring on a ruler and measure the inside diameter so that the left inner ring is on the 0 of the ruler. The measure in mm corresponds to your ring size.