You can find your toe size easily using the string method. Simply use a piece of string and circle it around the middle part of your toe as shown in the picture below.
The same method can be used for your thumb, knuckle or pinky.
Next, mark the parts of the string where the two ends meet and using a ruler, measure its length in millimeters. That number is your first size.
Again, using the same method, measure the widest part of your toe pad. The next number is your second size.
Finally, using these measurements, determine your size from a ring chart.