I didn’t understand the gauge, (It gave the gauge for one motif across by 4 rows, but I think it was maybe for 8 rows) so I started out with the size Large for an oversize tunic. I used the recommended 4.5 for the beginning chain and downsized to a 4.0 for the rest. Overall dimensions were not given so I guessed at that based on the measurement given for where to place seams and the photos. After a few rows, I measured across, and I thought mine was a little big even for a looser fit, so I frogged back to row 1, and made the S/M size this time. I have completed 16 rows so far and it measures 25” across. I hope this is about right for the large size. (Following a pattern for a smaller size than I want is not unusual for me as I crochet on the loose side.)