Spirit Airlines

The story in the figures

Spirit Airlines' passenger-miles per gallon rose 85% between 2000 and 2025, from 41.4 to 76.5. Most of that came from the aircraft: seat-miles per gallon rose 71%, while planes ran fuller, with 73% of seat-miles filled in 2000 against 78% in 2025.

The shape of the flying changed as well: the average flight went from 152 seats to 193. In general, larger aircraft spread fuel over more passengers.

Its best year was 2024, at 79.2 passenger-miles per gallon.

In 2020 the pandemic emptied the cabins: load factor dropped from 84% to 69%, and passenger-miles per gallon fell from 74.8 to 66.7. 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 2.2% above its 2019 level.

Against the all-airline figure for 2025 (60.6), Spirit Airlines was 26% better. On a 1,000 mile trip that works out to 127 kg of CO2 for one passenger, from burning jet fuel only.

What one seat costs the climate

CO2 for one passenger on Spirit Airlines, from burning jet fuel only.

• 64 kgover 500 miles
• 127 kgover 1,000 miles
• 255 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	76.5	0.127	97.6	78.4%	32.0	409	3,992
2024	79.2	0.123	96.1	82.4%	44.2	552	5,380
2023	76.3	0.128	93.9	81.3%	44.1	593	5,778
2022	75.4	0.129	92.1	81.9%	38.5	527	5,141
2021	73.8	0.132	93.7	78.8%	30.8	435	4,243
2020	66.7	0.146	96.5	69.1%	18.4	289	2,822
2019	74.8	0.130	88.8	84.3%	34.5	471	4,592
2018	74.2	0.131	88.0	84.3%	29.3	412	4,020
2017	71.3	0.137	85.8	83.2%	24.2	345	3,363
2016	72.5	0.135	86.1	84.2%	21.6	298	2,903
2015	70.9	0.138	84.1	84.3%	17.9	254	2,476
2014	70.6	0.138	81.8	86.3%	14.3	200	1,955
2013	69.8	0.140	80.5	86.7%	12.4	172	1,676
2012	67.3	0.145	79.0	85.2%	10.4	143	1,394
2011	67.3	0.145	78.6	85.6%	8.5	119	1,160
2010	62.1	0.157	75.8	82.0%	6.9	107	1,040
2009	61.4	0.159	77.2	79.5%	6.2	97	944
2008	60.3	0.162	75.0	80.3%	7.0	110	1,068
2007	60.4	0.162	74.8	80.7%	7.0	114	1,107
2006	54.9	0.177	66.9	82.1%	5.0	83	809
2005	49.0	0.199	61.3	80.0%	4.7	92	899
2004	44.1	0.221	56.7	77.8%	4.8	111	1,080
2003	49.9	0.196	63.2	79.0%	4.3	92	895
2002	43.9	0.222	59.8	73.4%	3.9	93	909
2001	43.9	0.222	59.5	73.7%	3.3	76	739
2000	41.4	0.235	57.0	72.6%	2.8	66	645

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The Spirit Airlines fleet

Spirit Airlines operated 129 passenger aircraft of its own in 2025. The average age was 7.5 years: 28% of the aircraft were under five years old and 0% were twenty or older. The oldest was an Airbus A320 built in 2010. That's the 3rd youngest of the 12 airlines ranked here.

In 2006 the average age was 4.1 years across 38 aircraft. It's older now by 3.4 years, and the fleet is bigger.

On the Airbus A320, Spirit Airlines fits 176 seats on average, against a median of 157 at the other airlines that fly it (142 to 184). 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.

Spirit Airlines aircraft by model, 2025

Model	Aircraft	Average seats	Other airlines, median seats	Average age
Airbus A320	60	176	157	10.8
Airbus A321	29	222	191	8.4
Airbus A321neo	21	229	194	0.8
Airbus A320neo	19	176	186	2.6

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: Spirit Airlines

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.