I am 411 & 105lbs. I got an XS. I plan on buying another one.  I work full time as a gardener. These are so comfortable, granted they are really long, which is totally expected given my height. They are more comfortable than my Carhartts. They aren't as thick or reinforced as typical workwear so I doubt theyll last as long. The one thing Id change is a bigger kangaroo pocket with a snap so I can hold my phone there without it falling out. I plan on buying the other color.