
When trying to decide on a size for you, simply measure your wrist. Once measured choose the closest appropriate band size and add the watch face size. After doing the math (adding the band size to the wrist size and then confirming to your wrist size) decide how you like to wear your watch set. If you like to wear it snug then your ok to use the default size you used when measuring. If you like to wear it loose then choose one band size up.
Example:
Wrist size 6.25"
An appropriate choice of band/face would be a 5" band and a 1.25" face. This is applicable if you like a snug fit.
If you would like a loose fit then you would choose a 5.5" band and the 1.25" face, or a 2" face and a 5" band.