The sizing on this jacket is comparable to other “alpha” sized jackets and is also in line with men’s clothing sizes, so choose the size you normally wear in jackets and shirts. If you want to double check sizing using a tape measure, refer to the chart below. Don’t be concerned that the belly dimensions are much bigger than your measurement—this is part of the “relaxed” styling. Side torso zippers expand the belly region another 5 inches or so if necessary (beyond what we show in the table here).
| Size | Max Chest | Max Belly |
| Small | 38 | 32 |
| Medium | 40 | 36 |
| Large | 44 | 38 |
| XL | 46 | 40 |
| XXL | 48 | 42 |
| XXXL | 50 | 44 |
| XXXXL | 52 | 46 |