I recommend reviewing Ten Thousand's fit metrics as the medium shirt I tested was on the shorter side (and I'm roughly 5'9"). The chest, shoulders, and arms all fit properly but I would've liked ...

Generally, three ounces is considered light, 4.5 to 5.3 ounces is medium, and six ounces and over is heavy. We’ve included plenty of options ranging from light- to heavyweight T-shirts.