The 737-800 has a maximum fuel capacity of 6,875 gallons, which it carries in fuel tanks in its wings, as seen here, and in a fuel tank located underneath the passenger cabin's midsection. Fully loaded, the jet can fly up to 3,159 miles without refueling.

The Boeing 737-800, a workhorse of the "Next Generation" family, has a maximum range of approximately 2,935 nautical miles (about 3,377 miles or 5,436 kilometers). This range allows it to comfortably handle short-to-medium-haul routes, such as transcontinental flights across the United States or flights between Europe and North Africa. However, the "actual" range in a commercial setting is often slightly lower once you factor in a full passenger load, heavy luggage, and the mandatory fuel reserves required by aviation authorities. For longer over-water routes, airlines often utilize the 737 MAX 8, which features improved fuel efficiency and an extended range of about 3,500 nautical miles. Despite being surpassed by newer models, the -800 remains incredibly popular because its range perfectly suits the vast majority of high-frequency "corridor" routes globally, such as those operated by Southwest, Ryanair, and American Airlines.