Boeing 737-700

The 737-700 was the first of the 737 Next Generation family: Southwest launched it and took the first delivery in December 1997, and it entered service in 1998. Southwest still flies more of them than anyone, which is why Southwest dominates this page.

A passenger jet wing seen from the window at sunset — Illustrative photo. It doesn't identify an aircraft type or airline. Photo: DaLiu, DepositPhotos Standard licence.

867gallons per airborne hour
68.7seat-miles per gallon
141seats per flight on average
1,421gallons burned per flight

What the figures say

Boeing 737-700 ranks 18 of 25 types for seat-miles per gallon in 2025, at 68.7. The Boeing 737-800, the most common type in the table, flew 79.1, so a gallon on the Boeing 737-700 carried a seat 13% less far. Over 1,000 miles, one seat on this type accounts for about 142 kg of CO2 from the fuel burned.

US airlines burned 979 million gallons on the Boeing 737-700 in 2025, 5.2% of the fuel burned on all scheduled passenger flying, over 1,128 thousand airborne hours and 689 thousand departures. The average flight spent 1.6 hours in the air and burned 1,421 gallons.

Since 2001, when it was first flown in volume, the type's figure has fallen from 69.3 to 68.7 seat-miles per gallon (0.9%). Its best year was 2020, at 76.5. The average flight got shorter, from 2.0 to 1.6 hours in the air, which tends to raise fuel burn per seat-mile, because take-off and climb take a larger share of the fuel on a short flight.

Airlines get different results from the same aircraft. Southwest Airlines flew 69.5 seat-miles per gallon on it and Alaska Airlines 59.5, a gap of 17%. The seat count explains most of it: Southwest Airlines put 143 seats on each flight against 124 at Alaska Airlines. Flight length differs too, at 1.6 hours in the air per flight for Southwest Airlines and 1.4 for Alaska Airlines, and longer flights burn less fuel per seat-mile, which helps Southwest Airlines. What's left comes from taxi and holding time, weight, engines, how each airline operates and how it allocates fuel to types when it reports, and the filings can't separate those.

What one seat costs the climate

CO2 for one seat on a Boeing 737-700, from the fuel burned, at the 2025 average.

71 kgover 500 miles
142 kgover 1,000 miles
284 kgover 2,000 miles

Boeing 737-700 seat-miles per gallon across all US airlines flying it, by year, from the first year it was flown in volume.

Who flies it, and how they burn

Boeing 737-700 by airline, 2025

Airline	Fuel (million gallons)	Gallons per airborne hour	Seats per flight	Hours per flight	Seat-miles per gallon
Southwest Airlines	857	868	143	1.6	69.5
United Airlines	84	867	126	2.0	62.4
Alaska Airlines	20	871	124	1.4	59.5

Seats on the Boeing 737-700, airline by airline

The Boeing 737-700 has 120 seats at Alaska Airlines and 143 at Southwest Airlines, 19% more on the same model. The seat count is what each airline reports for its own aircraft in 2025, for airlines with 10 or more.

Boeing 737-700 fleets, 2025

Airline	Aircraft	Average seats	Fewest to most	Average age
Alaska Airlines	11	120.0	120	25.3
United Airlines	40	124.0	124	26.3
Southwest Airlines	305	143.0	143	19.1

See every airline's fleet on the fleets page.

Similar-sized aircraft

These types carry within about 25 seats of the Boeing 737-700, so they compete for the same routes.

Airbus A320-20074.0 seat-miles per gallon, 961 gallons per hour Airbus A220-30072.2 seat-miles per gallon, 804 gallons per hour Airbus A31958.1 seat-miles per gallon, 952 gallons per hour

How to read this. Fuel is what airlines issued to the type in 2025, as filed with the US Bureau of Transportation Statistics, counted only for the hours spent on scheduled passenger flights and divided by the hours in the air. It includes fuel burned taxiing and holding, so it's higher than the cruise figure in a manual. CO2 is 9.75 kg per gallon of jet fuel.

More from Boeing

Browse the Boeing manufacturer hub and its other profiled types:

Nearby in fuel efficiency

Types on either side of this one in the seat-miles per gallon table, regardless of size:

Boeing 767-400ER63.1 seat-miles per gallon Boeing 757-20068.5 seat-miles per gallon Airbus A330-30069.4 seat-miles per gallon Airbus A220-30072.2 seat-miles per gallon

Source: US Bureau of Transportation Statistics (BTS), Schedule T-2 fuel and airborne hours; US EPA jet-fuel CO2 factor. See the methodology and flight-hour definitions.

Back to all aircraft types, or see how the airlines compare on the airline pages.