The Boeing 737-800, also called the Boeing 738, seats between about 150 and 180 passengers. The plane's exact seating capacity varies depending on each airline's preference for number and type of seating classes.
For example, as of September 2015, the United Airlines fleet contains six versions of the Boeing 738. Version one has 20 first class seats and 132 economy class seats, while version six has 16 first class seats and 150 economy class seats. Each version's economy class also offers a varying number of seats with increased leg room. Southwest Airlines' Boeing 738, on the other hand, contains 175 seats, all of which are in economy class. Delta Airlines' Boeing 738 model has 20 first class seats and 144 main cabin seats, 18 of which offer extra leg room.