Option 1: Measure a ring that fits you.
If you have a ring that already fits your finger, measure the inside diameter (any ruler works, just remember 1 cm = 10 mm). Place a ruler on top of the ring and measure the inside from edge to edge in millimeters. Then, use the size chart below to compare the diameter with the conversion chart to find your ring size.
Example:
As you can see, the inside diameter of this ring is 2.1 centimeters, or 21 millimeters.
Using the size chart above, the ring size is 11.5 USA.
If you’re not sure between two sizes, we recommend going with the bigger one.
Notice where the ruler is placed. The ring is exactly 2.1 centimeters (21 mm) in the inside diameter: keep in mind a slight variation could mean a bigger size. Don’t measure the outside diameter, it could mean this ring would be 2.2 cms and that means a different size.
Wrap a string, tape, or strip of paper around the base of your finger (ideally have a friend do it for more precision). Mark where the string, tape or paper overlaps with a pen. Measure the length in millimeters.
Use the size chart below to compare the diameter and find your ring size.
Example:
Step 1:
As you can see, the mark has to be where the tape overlaps.
Step 2:
As you can see, the tape measures 6.6 centimeters, or 66 millimeters. Using the size chart above, the measure would be a 11.5 USA.
Note: YouTube can be very useful! Ideally do this process with a friend and do it a couple of times until you feel you have the right size.
* Keep in mind the most precise way of knowing your size is using a ring sizer or having your size measured directly by the jeweler.