How fuel-efficient is your airline?
Our 2025 report card grades 13 US airlines on how far they carry a passenger per gallon of jet fuel. Frontier Airlines flew 83.0 passenger-miles per gallon. American Airlines flew 55.9.
See every grade- 60.6passenger-miles per gallon, all ranked airlines together
- +58%better than in 2000
- 0.161 kgCO2 per passenger-mile
- 182.6 milliontonnes of CO2 from scheduled flying, 2025
The grades
Grades compare each airline with the all-airline figure of 60.6 passenger-miles per gallon. They measure fuel use per passenger, not safety, comfort or price.
- Aat least 10% better than the all-airline figure
6 airlines - B3% to 10% better
2 airlines - Cwithin 4% below to 3% above
3 airlines - D4% to 10% worse
2 airlines - Fmore than 10% worse
0 airlines
83.0 passenger-miles per gallon
Average trip: 938 miles per passenger.
- CO2 over 1,000 miles
- 118 kg
- Seats filled
- 78%
- Seats per flight
- 209
79.9 passenger-miles per gallon
Average trip: 1,666 miles per passenger.
- CO2 over 1,000 miles
- 122 kg
- Seats filled
- 83%
- Seats per flight
- 170
77.6 passenger-miles per gallon
Average trip: 1,276 miles per passenger.
- CO2 over 1,000 miles
- 126 kg
- Seats filled
- 84%
- Seats per flight
- 186
76.5 passenger-miles per gallon
Average trip: 978 miles per passenger.
- CO2 over 1,000 miles
- 127 kg
- Seats filled
- 78%
- Seats per flight
- 193
71.6 passenger-miles per gallonAllocation range: 67.23 to 71.61 passenger-miles per gallon.
Order uncertain with Allegiant Air: the results overlap. Treat these results as tied.
Average trip: 1,293 miles per passenger.
- CO2 over 1,000 miles
- 136 kg
- Seats filled
- 83%
- Seats per flight
- 96
69.0 passenger-miles per gallon
Order uncertain with Alaska Airlines: the results overlap. Treat these results as tied.
Average trip: 915 miles per passenger.
- CO2 over 1,000 miles
- 141 kg
- Seats filled
- 83%
- Seats per flight
- 175
64.8 passenger-miles per gallon
Average trip: 1,357 miles per passenger.
- CO2 over 1,000 miles
- 150 kg
- Seats filled
- 82%
- Seats per flight
- 158
64.3 passenger-miles per gallon
Average trip: 821 miles per passenger.
- CO2 over 1,000 miles
- 152 kg
- Seats filled
- 77%
- Seats per flight
- 161
62.0 passenger-miles per gallon
Average trip: 841 miles per passenger.
- CO2 over 1,000 miles
- 157 kg
- Seats filled
- 76%
- Seats per flight
- 167
60.5 passenger-miles per gallon
Average trip: 883 miles per passenger.
- CO2 over 1,000 miles
- 161 kg
- Seats filled
- 77%
- Seats per flight
- 135
58.2 passenger-miles per gallonAllocation range: 58.24 to 58.34 passenger-miles per gallon.
Average trip: 1,480 miles per passenger.
- CO2 over 1,000 miles
- 167 kg
- Seats filled
- 82%
- Seats per flight
- 126
58.0 passenger-miles per gallonAllocation range: 57.65 to 57.96 passenger-miles per gallon.
Average trip: 1,219 miles per passenger.
- CO2 over 1,000 miles
- 168 kg
- Seats filled
- 84%
- Seats per flight
- 127
55.9 passenger-miles per gallonAllocation range: 55.89 to 56.62 passenger-miles per gallon.
Average trip: 1,118 miles per passenger.
- CO2 over 1,000 miles
- 174 kg
- Seats filled
- 84%
- Seats per flight
- 123
What your seat costs the climate
CO2 for one passenger on a trip of each length, cleanest airline first. CO2 from burning jet fuel only, at the EPA factor of 9.75 kg per gallon.
| Airline | Grade | 500 miles | 1,000 miles | 2,000 miles |
|---|---|---|---|---|
| Frontier Airlines | A | 59 kg | 118 kg | 235 kg |
| Hawaiian Airlines | A | 61 kg | 122 kg | 244 kg |
| Sun Country Airlines | A | 63 kg | 126 kg | 251 kg |
| Spirit Airlines | A | 64 kg | 127 kg | 255 kg |
| Alaska Airlines | A | 68 kg | 136 kg | 272 kg |
| Allegiant Air | A | 71 kg | 141 kg | 283 kg |
| JetBlue | B | 75 kg | 150 kg | 301 kg |
| Southwest Airlines | B | 76 kg | 152 kg | 303 kg |
| Avelo Airlines | C | 79 kg | 157 kg | 315 kg |
| Breeze Airways | C | 81 kg | 161 kg | 322 kg |
| United Airlines | C | 84 kg | 167 kg | 335 kg |
| Delta Air Lines | D | 84 kg | 168 kg | 336 kg |
| American Airlines | D | 87 kg | 174 kg | 349 kg |
| All airlines | 80 kg | 161 kg | 322 kg |
Why the grades differ
Passenger-miles per gallon is seat-miles per gallon multiplied by load factor. The first is about the aircraft and how the airline flies it. The second is how full the seats are.
The aircraft
Seat-miles per gallon runs from 66.8 to 105.7. Frontier Airlines gets 105.7 and American Airlines gets 66.8.
How full the seats are
Load factor runs from 76% to 84%. Frontier Airlines fills 78% of its seats, American Airlines fills 84%. The aircraft side varies more across the table.
What the grade leaves out
Fuel burned for cargo in the hold isn't separated out, so airlines with large widebody fleets carry some fuel that belongs to freight. See the methodology.
Then and now
The ranked airlines together went from 38.4 to 60.6 passenger-miles per gallon between 2000 and 2025.
All airlines
- Alaska Airlines grade A
- Allegiant Air grade A
- American Airlines grade D
- Avelo Airlines grade C
- Breeze Airways grade C
- Delta Air Lines grade D
- Frontier Airlines grade A
- Hawaiian Airlines grade A
- JetBlue grade B
- Southwest Airlines grade B
- Spirit Airlines grade A
- Sun Country Airlines grade A
- United Airlines grade C
- AirTran Airways 2000 to 2011
- Aloha Airlines 2000 to 2007
- America West Airlines 2000 to 2007
- ATA Airlines 2000 to 2007
- Continental Airlines 2000 to 2011
- Midway Airlines 2000 to 2001
- Midwest Airline 2000 to 2009
- National Airlines 2000 to 2002
- Northwest Airlines 2000 to 2009
- Trans World Airlines 2000 to 2001
- US Airways 2000 to 2015
- USA 3000 Airlines 2004 to 2010
- Vanguard Airlines 2000 to 2002
- Virgin America 2008 to 2017
Browse the full airline list, see the long-run trends, or download the data.