Boeing 737 MAX 9

The 737 MAX 9 is the longer sibling of the MAX 8. United and Alaska are its main US operators. Like the MAX 8, it has no flying in 2020, because the MAX fleet was grounded from March 2019 until the end of 2020.

The nose of a four-engine airliner at a gate in warm evening light — Illustrative photo. It doesn't identify an aircraft type or airline. Photo: tlovely, DepositPhotos Standard licence.

828gallons per airborne hour
100.3seat-miles per gallon
179seats per flight on average
2,655gallons burned per flight

What the figures say

Boeing 737 MAX 9 ranks 3 of 25 types for seat-miles per gallon in 2025, at 100.3. The Boeing 737-800, the most common type in the table, flew 79.1, so a gallon on the Boeing 737 MAX 9 carried a seat 27% further. Over 1,000 miles, one seat on this type accounts for about 97 kg of CO2 from the fuel burned.

The older Boeing 737-900ER flew 81.4 seat-miles per gallon in 2025. The Boeing 737 MAX 9 is 23% ahead, with 179 seats per flight against 179. Its fuel burn per airborne hour is 828 gallons against 992.

US airlines burned 536 million gallons on the Boeing 737 MAX 9 in 2025, 2.9% of the fuel burned on all scheduled passenger flying, over 647 thousand airborne hours and 202 thousand departures. The average flight spent 3.2 hours in the air and burned 2,655 gallons.

Since 2022, when it was first flown in volume, the type's figure has fallen from 102.4 to 100.3 seat-miles per gallon (2.1%).

Airlines get different results from the same aircraft. Alaska Airlines flew 102.8 seat-miles per gallon on it and United Airlines 98.3, a gap of 4.5%. It isn't the seat count: Alaska Airlines put 178 seats on each flight and United Airlines 179. Flight length differs too, at 3.4 hours in the air per flight for Alaska Airlines and 3.1 for United Airlines, and longer flights burn less fuel per seat-mile, which helps Alaska 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 MAX 9, from the fuel burned, at the 2025 average.

49 kgover 500 miles
97 kgover 1,000 miles
194 kgover 2,000 miles

Boeing 737 MAX 9 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 MAX 9 by airline, 2025

Airline	Fuel (million gallons)	Gallons per airborne hour	Seats per flight	Hours per flight	Seat-miles per gallon
United Airlines	301	840	179	3.1	98.3
Alaska Airlines	235	812	178	3.4	102.8

Seats on the Boeing 737 MAX 9, airline by airline

The Boeing 737 MAX 9 has 178 seats at Alaska Airlines and 179 at United Airlines, 1% 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 MAX 9 fleets, 2025

Airline	Aircraft	Average seats	Fewest to most	Average age
Alaska Airlines	80	178.0	178	2.3
United Airlines	120	179.0	179	2.6

See every airline's fleet on the fleets page.

Similar-sized aircraft

These types carry within about 25 seats of the Boeing 737 MAX 9, so they compete for the same routes.

Airbus A321neo105.0 seat-miles per gallon, 889 gallons per hour Airbus A320neo100.6 seat-miles per gallon, 780 gallons per hour Boeing 737 MAX 896.8 seat-miles per gallon, 800 gallons per hour Boeing 737-900ER81.4 seat-miles per gallon, 992 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 787-1086.2 seat-miles per gallon Boeing 737 MAX 896.8 seat-miles per gallon Airbus A320neo100.6 seat-miles per gallon Airbus A321neo105.0 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.