Small
I’m 5’10.5” (179 cm) and have a 26 inch waist (68 cm) and I got a L and it fit great! Would recommend this size to others! I was expecting the color of the shirt to be more olive toned, but unfortunately it was more of a neutral, it wasn’t a very warm color. That’s the one drawback, other than that I like that the fabric is breathable, the fit is great and it’s comfortable, so I think it’s a great shirt.