Small/Extra Small - Fits up to 5' 0" tall.
Medium - Fits up to 5' 8" tall.
Large - Fits up to 6' 3" tall.
Extra Large - Fits up to 6' 8" tall.
*The Napsack can be worn in many ways. How you plan to wear it will influence your sizing decision. If you plan to primarily sleep in it with the bottom cinched closed, we recommend you size up so that you have a comfortable amount of space for your feet.*