Zena Sizing:

Vest Size* 
Fit to waist size so upper band is secure around waist:
XS- 24" to 30"
SM- 24" to 30"
MD- 26" to 34"
LG- 28" to 38"
XL- 41" to 49"

Front Panel Size* 
Fit to Chest/ Bust Size:
SM- 30" to 34"
MD- 34" to 37"
LG- 37" to 42"
XL-37" to 42"

Shoulder Section**
Fit to torso length, size so upper waist band is at natural waist.
XS- 12" to 15"
SM- 13" to 16"
MD- 15" to 18"
LG-  17" to 19
XL-19" to 21"