I personally like to use midshaft measurements for
Girth. If I used base measurements I could claim to be bigger.
Look at it this way (purely an examply)... if your entire shaft was 4.5\"
Girth and your glans was 7\"
Girth, would you say you have a 7\" thick
Dick? I think that 4.5\"
Girth with a big mushroom head is a better description. So to answer your question, I would use shaft measurements
Girth.