Allegiant Air

The story in the figures

Allegiant Air's passenger-miles per gallon rose 53% between 2005 and 2025, from 45.1 to 69.0. Most of that came from the aircraft: seat-miles per gallon rose 48%, while planes ran fuller, with 80% of seat-miles filled in 2005 against 83% in 2025.

The shape of the flying changed as well: the average flight went from 147 seats to 175, and the average passenger flew 1,059 miles per segment in 2005 and 915 in 2025. In general, larger aircraft spread fuel over more passengers, and shorter flights spend a larger share of their fuel on takeoff and climb.

Its best year was 2022, at 70.9 passenger-miles per gallon, and its latest figure sits 2.8% below that.

In 2020 the pandemic emptied the cabins: load factor dropped from 84% to 60%, and passenger-miles per gallon fell from 68.1 to 51.9. A flight burns most of its fuel whether the seats are full or not, which is why an empty year looks so bad per passenger. By 2025 the figure was 1.2% above its 2019 level.

Against the all-airline figure for 2025 (60.6), Allegiant Air was 14% better. On a 1,000 mile trip that works out to 141 kg of CO2 for one passenger, from burning jet fuel only.

What one seat costs the climate

CO2 for one passenger on Allegiant Air, from burning jet fuel only.

• 71 kgover 500 miles
• 141 kgover 1,000 miles
• 283 kgover 2,000 miles

Year-by-year figures

Year	Passenger-miles per gallon	kg CO2 per passenger-mile	Seat-miles per gallon	Load factor	Passengers (millions)	Fuel (million gallons)	CO2 (thousand tonnes)
2025	69.0	0.141	83.5	82.5%	18.6	247	2,411
2024	68.9	0.141	81.9	84.2%	16.9	223	2,179
2023	70.9	0.137	82.0	86.5%	17.3	222	2,162
2022	70.9	0.137	82.9	85.5%	16.7	216	2,105
2021	59.5	0.164	84.0	70.8%	13.6	202	1,974
2020	51.9	0.188	86.5	60.0%	8.6	148	1,444
2019	68.1	0.143	80.7	84.4%	14.9	193	1,879
2018	64.9	0.150	76.2	85.3%	13.7	188	1,836
2017	60.0	0.163	71.3	84.1%	12.2	183	1,786
2016	60.0	0.163	70.2	85.5%	11.1	170	1,657
2015	60.0	0.162	69.1	86.8%	9.4	148	1,442
2014	60.6	0.161	67.9	89.3%	8.1	128	1,247
2013	59.1	0.165	66.5	88.9%	7.1	118	1,154
2012	55.3	0.176	61.8	89.5%	6.6	113	1,099
2011	52.7	0.185	57.5	91.7%	5.8	101	981
2010	51.7	0.189	56.9	90.8%	5.6	101	982
2009	51.5	0.189	56.9	90.4%	4.9	87	847
2008	50.2	0.194	55.8	90.0%	3.9	70	679
2007	46.9	0.208	56.5	83.1%	3.0	61	590
2006	46.9	0.208	58.2	80.7%	1.9	42	414
2005	45.1	0.216	56.6	79.7%	1.0	23	226

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The Allegiant Air fleet

Allegiant Air operated 123 passenger aircraft of its own in 2025. The average age was 13.8 years: 13% of the aircraft were under five years old and 25% were twenty or older. The oldest was an Airbus A320 built in 1997. That's the 8th youngest of the 12 airlines ranked here.

In 2006 the average age was 16.1 years across 25 aircraft. It's younger now by 2.3 years, and the fleet is bigger.

On the Airbus A320, Allegiant Air fits 184 seats on average, against a median of 157 at the other airlines that fly it (142 to 176). Seats on the same aircraft are one reason fuel per seat and fuel per passenger differ between airlines: the fuel burned by a given plane is much the same, and more seats share it.

Allegiant Air aircraft by model, 2025

Model	Aircraft	Average seats	Other airlines, median seats	Average age
Airbus A320	79	184	157	14.4
Airbus A319	28	156	128	19.8
Boeing 737 MAX 8	16	190	172	0.3

All the airlines are compared on the fleets page.

Neighbours in the ranking

Nearby airline results

These airlines sit nearby by passenger-miles per gallon in their last data year. Historical airlines have different end years, shown here, so this isn't a same-year ranking.

Airline references

• Wikipedia: Allegiant Air
• Official site: Allegiant Air

Source: US Bureau of Transportation Statistics (BTS), Schedule P-12(a) fuel, T-100 traffic and regional Schedule T-2 filings; US EPA jet-fuel CO2 factor. See the methodology.