The 60L does fit in the overhead bins on most airplanes even when full, and it holds a lot of stuff. I've fit two weeks worth of clothes, multiple pairs of shoes, towels, etc. into this bag for a long trip.

The Patagonia Black Hole Duffel 60L (now largely superseded by the 55L and 70L versions in the 2026 lineup) is generally too large to be considered a standard carry-on for most commercial airlines. The typical international carry-on size limit is approximately 40–45 liters with dimensions around 56×36×23 cm. At 60 liters, the bag's physical dimensions when fully packed exceed these limits, especially in length. While some travelers "get away with it" on large domestic US flights by not filling the bag to its maximum capacity—allowing it to be squashed into the overhead bin—it is a significant risk. If a gate agent asks you to place it in the "sizer" box, it will almost certainly fail. For a guaranteed carry-on experience with Patagonia, the 40L Black Hole Duffel is the specifically designed "carry-on" size that fits within the legal requirements of most major airlines worldwide without the need for "coaxing" or risk of gate-checking.