Size charts have been provided as general guide for determining fit. However, there might be 1-2cm differences in the measurement given due to the different stretchable quality of the material.
In Between Sizes?
That's easier said than done. Because what do you do if you are in between two size?
Well, that's up to you.
Do you like a tight fit? Go for the smaller size.
Loving a loose fit? Go for the larger size.