Sizing charts for most items sold on Merchtable are available through the links below. 

Since the garments we sell are printed in a wide variety of sizes from different manufacturers, we provide these as a general estimate. 

To help get the best possible fit we suggest measuring a comfortable shirt you already own. 
Measure from armpit to armpit, and from the collar to the bottom of the garment. You can compare these numbers to the estimated measurements provided below. Please keep in mind we typically factor in a plus/minus of around a half inch to the measurements to account for variations in production.