A plane like a Boeing 747 uses approximately 1 gallon (about 4 liters) of fuel every second. Over the course of a 10-hour flight, it might burn 36,000 gallons (150,000 liters). The 747 burns approximately 5 gallons of fuel per mile (12 liters of fuel per kilometer).
This sounds like a tremendously poor miles-per-gallon rating. But consider that a 747 can carry as many as 568 people. Let's call it 500 people to make the math easier. A 747 is transporting 500 people 1 mile using 5 gallons of fuel. That means the plane is burning 0.01 gallons per person per mile (5/500). In other words, the plane is getting 100 miles per gallon (42 kilometers per liter) per person! Not bad when you consider that the 747 is flying at 550 mph (900 kph).
The current reigning champ for the world's largest jet airliner, the Airbus A380, is even more efficient. The multi-story jumbo jet burns an average of 4,600 gallons (11,400 liters) of fuel per hour. That's a bit more than the 747. The A380 can also carry more than 800 passengers at maximum capacity. That's about a 20 percent increase in per-passenger fuel efficiency over the older 747.
Let's compare flying to driving: The typical car gets about 25 miles per gallon. Driving from New York City to Los Angeles would take about 2,797 miles (4,501 kilometers) or 112 gallons (509 liters) of gas. With two passengers (the average car occupancy in the U.S.), that works out to 56 gallons per person (2,797/25/2). Flying that route would take about 6 hours. The flight would use 5,325 gallons of jet fuel. But assuming 200 people on the flight would work out to 27 gallons of fuel per person.