Boeing 737-900ER

The 737-900ER is the extended-range 737-900, the longest of the 737 Next Generation family. In this data it's flown by Delta, United and Alaska.

A passenger jet wing above clouds under a blue sky — Illustrative photo. It doesn't identify an aircraft type or airline. Photo: paulshuang, DepositPhotos Standard licence.

992gallons per airborne hour
81.4seat-miles per gallon
179seats per flight on average
2,403gallons burned per flight

What the figures say

Boeing 737-900ER ranks 6 of 25 types for seat-miles per gallon in 2025, at 81.4. The Boeing 737-800, the most common type in the table, flew 79.1, so a gallon on the Boeing 737-900ER carried a seat 2.9% further. Over 1,000 miles, one seat on this type accounts for about 120 kg of CO2 from the fuel burned.

US airlines burned 1,118 million gallons on the Boeing 737-900ER in 2025, 6.0% of the fuel burned on all scheduled passenger flying, over 1,127 thousand airborne hours and 465 thousand departures. The average flight spent 2.4 hours in the air and burned 2,403 gallons.

Since 2016, when it was first flown in volume, the type's figure has fallen from 87.7 to 81.4 seat-miles per gallon (7.2%). Its best year was 2018, at 90.7. The average flight got shorter, from 2.8 to 2.4 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. Alaska Airlines flew 88.5 seat-miles per gallon on it and Delta Air Lines 79.0, a gap of 12%. It isn't the seat count: Alaska Airlines put 178 seats on each flight and Delta Air Lines 179. Flight length differs too, at 3.2 hours in the air per flight for Alaska Airlines and 2.1 for Delta Air Lines, 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 737-900ER, from the fuel burned, at the 2025 average.

60 kgover 500 miles
120 kgover 1,000 miles
240 kgover 2,000 miles

Boeing 737-900ER 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 737-900ER by airline, 2025

Airline	Fuel (million gallons)	Gallons per airborne hour	Seats per flight	Hours per flight	Seat-miles per gallon
Delta Air Lines	485	1,013	179	2.1	79.0
United Airlines	380	1,008	179	2.5	79.6
Alaska Airlines	253	932	178	3.2	88.5

Seats on the Boeing 737-900ER, airline by airline

The Boeing 737-900 and 900ER has 173 seats at United Airlines and 181 at Alaska Airlines, 5% 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 737-900ER fleets, 2025

Airline	Aircraft	Average seats	Fewest to most	Average age
United Airlines	148	173.0	173	13.4
Delta Air Lines	163	179.2	173 to 180	9.5
Alaska Airlines	79	181.0	181	9.4

See every airline's fleet on the fleets page.

Similar-sized aircraft

These types carry within about 25 seats of the Boeing 737-900ER, 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 9100.3 seat-miles per gallon, 828 gallons per hour Boeing 737 MAX 896.8 seat-miles per gallon, 800 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 737-80079.1 seat-miles per gallon Boeing 757-30079.3 seat-miles per gallon Boeing 787-1086.2 seat-miles per gallon Boeing 737 MAX 896.8 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.