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Rankings / Routes / San Francisco to Las Vegas

2025 flights

San Francisco to Las Vegas

Between San Francisco and Las Vegas, 3.7 million passengers flew nonstop in 2025, on 29 thousand flights of about 404 miles and 1.1 hours in the air. The average passenger accounted for about 71 kg of CO2 from the fuel burned, from 62 kg on Frontier Airlines to 119 kg on SkyWest Airlines.

San Francisco to Las Vegas is Southwest's route: 54% of the passengers, up from 48% in 2019, as Alaska's share fell from 13% to 7%. The route as a whole got 9% cleaner, from 79 kg to 71 kg a passenger, and the carrier that moved it was the biggest one: Southwest went from 79 kg to 71 kg.

The smaller airlines went the other way. Spirit's figure rose from 58 kg to 64 kg and Frontier's from 53 kg to 62 kg, so the route improved because the largest airline did, not because all of them did.

  • 71 kgCO2 per passenger, average
  • 404 milesabout 1.1 hours in the air
  • 3.7 millionpassengers in 2025
  • 77%of seats filled

CO2 per passenger, airline by airline

CO2 per passenger by airline, San Francisco to Las VegasBar chart of kilograms of CO2 per passenger on each airline between San Francisco and Las Vegas in 2025.050100Frontier Airlines62 kgSpirit Airlines64 kgSouthwest Airlines71 kgAlaska Airlines76 kgUnited Airlines77 kgSkyWest Airlines119 kg
CO2 per passenger by airline, San Francisco to Las VegasBar chart of kilograms of CO2 per passenger on each airline between San Francisco and Las Vegas in 2025.050100Frontier Airlines62 kgSpirit Airlines64 kgSouthwest Airlines71 kgAlaska Airlines76 kgUnited Airlines77 kgSkyWest Airlines119 kg
Kilograms of CO2 per passenger, one way, 2025. Fuel burned only. Less is better.
San Francisco to Las Vegas by airline, 2025
AirlineShare of passengersFlights (thousands)Main aircraftSeats per flightSeats filledkg CO2 per passenger
Southwest Airlines54%15.7Boeing 737 MAX 8, Boeing 737-70016578%71
United Airlines19%5.4Boeing 737-800, Boeing 737 MAX 917377%77
Spirit Airlines10%2.6Airbus A320neo, Airbus A320-20017977%64
Frontier Airlines9%2.2Airbus A320neo, Airbus A321neo19977%62
Alaska Airlines7%2.1Boeing 737-900ER, Boeing 737 MAX 917474%76
SkyWest Airlines1%0.7Embraer 1757280%119

What explains the differences

It's number 15 of the 100 busiest city pairs by passengers, and number 75 for the lowest CO2 per mile flown (0.18 kg per passenger-mile, number 1 being the lowest). A typical route of 404 miles in this set comes out at about 78 kg, so this one is 8.6% below it.

The flights use more than one pair of airports: LAS to SFO (44%), LAS to SJC (28%), LAS to OAK (28%). The figures here cover all of them.

The airlines on this route differ by 94% per passenger. Frontier Airlines burned 963 gallons per flight and 153 passengers on each, and SkyWest Airlines 709 gallons and 58 passengers. The gap comes from how many passengers share each flight, not from fuel burned per flight. Frontier Airlines flew 77% full here against 80% for SkyWest Airlines, flying mostly Airbus A320neo against Embraer 175.

For comparison, the EPA default factor for a flight of this length (0.129 kg per passenger-mile) would give 52 kg. The EPA figure is a national average for flights of that length. The measured figure for this route is 37% higher.

2019 compared with 2025

In 2019 the route carried 4.1 million passengers on 34 thousand flights. In 2025 it carried 3.7 million, down 9%, on 29 thousand flights, down 17%. The average flight had 151 seats then and 168 now, and 78% of them were filled against 77%.

CO2 per passenger was 79 kg in 2019 and 71 kg in 2025, down 9.4%. Fuel burned per flight was down 0.8% (957 gallons to 950) and passengers per flight were up 9.5% (118 to 130). The distance flown was about the same (404 miles then, 404 now).

Southwest Airlines led in both years, with 48% of passengers in 2019 and 54% in 2025. Alaska Airlines lost the most, 13% to 7%. SkyWest Airlines didn't have 1% of the passengers in 2019 and now carries 1%. Compass Airlines and Allegiant Air no longer reach 1% of passengers, having had 5% in 2019.

Airline by airline, Alaska Airlines went from 89 kg to 76 kg per passenger (146 seats per flight to 174, main aircraft Airbus A319 then and Boeing 737-900ER now); Frontier Airlines went from 53 kg to 62 kg per passenger (195 seats per flight to 199, main aircraft Airbus A320neo in both years).

San Francisco to Las Vegas, 2019 and 2025
Measure20192025
Passengers (thousands)4,0783,718
Flights (thousands)34.528.7
Seats filled78%77%
Gallons of fuel per flight957950
kg CO2 per passenger7971
CO2 per passenger by airline, 2019 and 2025, San Francisco to Las VegasBar chart of kilograms of CO2 per passenger on San Francisco to Las Vegas for each major airline in 2019 and in 2025.020406080Southwest Airlines 201979 kgSouthwest Airlines 202571 kgUnited Airlines 201979 kgUnited Airlines 202577 kgSpirit Airlines 201958 kgSpirit Airlines 202564 kgFrontier Airlines 201953 kgFrontier Airlines 202562 kg
CO2 per passenger by airline, 2019 and 2025, San Francisco to Las VegasBar chart of kilograms of CO2 per passenger on San Francisco to Las Vegas for each major airline in 2019 and in 2025.0255075Southwest Airlines 201979 kgSouthwest Airlines 202571 kgUnited Airlines 201979 kgUnited Airlines 202577 kgSpirit Airlines 201958 kgSpirit Airlines 202564 kgFrontier Airlines 201953 kgFrontier Airlines 202562 kg
Kilograms of CO2 per passenger on the airlines that flew the route in both years. 2019 figures use that year's filings and estimated aircraft fuel rates, with type-average replacements for missing or outlying filings as described in the methodology. Less is better.

San Francisco to Las Vegas and back: time in the air

The time in the air is almost the same each way: 67 minutes on average from San Francisco to Las Vegas and 67 minutes back. A difference of 1 minute is within what routing and congestion alone produce.

Time in the air by direction, 2025
DirectionAverage minutes in the airFlights
San Francisco to Las Vegas67.314,341
Las Vegas to San Francisco66.514,355

Fly or drive

Driving is about 473 miles by road, which we estimate as 1.17 times the straight-line distance. An average car emits about 140 kg of CO2 on the trip, at the EPA figure of 0.297 kg per vehicle-mile. Alone, that's 96% more than the 71 kg for a passenger on the flight.

With 2 people in the car, driving comes out lower per person than the flight (70 kg each, and 35 kg each for four). A larger SUV or pickup (0.394 kg per mile) would emit about 186 kg per vehicle.

CO2 per person by way of travel, San Francisco to Las VegasBar chart of kilograms of CO2 per person flying, driving or taking the train between San Francisco and Las Vegas.050100Flight, average71 kgCar, driver alone140 kgCar, 2 people70 kgCar, 4 people35 kg
CO2 per person by way of travel, San Francisco to Las VegasBar chart of kilograms of CO2 per person flying, driving or taking the train between San Francisco and Las Vegas.050100Flight, average71 kgCar, driver alone140 kgCar, 2 people70 kgCar, 4 people35 kg
CO2 per person, San Francisco to Las Vegas. Driving figures divide one car's emissions between the people in it. See flying vs driving for other trip lengths.

Flights are listed under the airline that operates them, so regional flying appears under the regional. How the CO2 and drive figures are worked out is in the methodology.

What to take from it

'San Francisco' is three airports and only 44% of the passengers use SFO itself, with San Jose and Oakland taking the rest. The flight is 67 minutes in the air in both directions, so there's no wind effect to speak of.

At 473 road miles, a car with two people comes to 70 kg each, the same as the flight's 71 kg, and a car with four to 35 kg each. Passengers are 9% below 2019.

Routes with shared cities or nearby CO2 per mile

Los Angeles to San Francisco75 kg CO2 per passenger over 337 milesLos Angeles to Las Vegas53 kg CO2 per passenger over 227 milesNew York to San Francisco414 kg CO2 per passenger over 2,578 milesSan Francisco to San Diego78 kg CO2 per passenger over 436 milesSan Francisco to Seattle119 kg CO2 per passenger over 683 milesAtlanta to Orlando71 kg CO2 per passenger over 404 milesChicago to Atlanta107 kg CO2 per passenger over 601 milesAtlanta to Tampa73 kg CO2 per passenger over 406 miles

Airports on this route: Harry Reid International Airport, San Francisco International Airport, San Jose International Airport, Oakland San Francisco Bay Airport.

Airport and airline references

Source: US Bureau of Transportation Statistics (BTS), T-100 traffic and Schedule T-2 fuel filings; US EPA transport emission factors. See the methodology.

See all routes, or how the airlines compare overall on the airline pages.