ISO Ring Size Standard 8653
1. Scope and Field of Application
This International Standard specifies the method for measuring the size of rings for the purposes of designating ring-sizes to be used in jewellery.
Ring-size: The inner circumference of the ring expressed in millimeters.
The inner circumference of the ring should be measured using a tapered ring-gauge (ring-stick) with the following characteristics:
a) length of the measurement scale: 160 ± 0.5 mm
b) minimum ring-size: 41
c) maximum ring-size: 76
d) material: metal, or material with equivalent wear resistance.
The size of the ring shall be designated by the number of this International Standard followed by the inner circumference of the ring expressed in millimeters rounded to the nearest millimeter. Example: Designation for a ring with a ring-size of 43mm measured in accordance with this International Standard : Ring-size IS0 8653 - 43