Bella+Canvas sizes

Code Size name Chest to fit
XS Extra Small 31"–34"
S Small 34"–37"
M Medium 38"–41"
L Large 42"–45"
XL Extra Large 46"–49"
2XL Double Extra Large 50"–53"
3XL Triple Extra Large 54"–57"

Taken from Bella+Canvas Unisex Fit & Size Chart.