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Rankings / Routes / Denver to Las Vegas

2025 flights

Denver to Las Vegas

Between Denver and Las Vegas, 2.0 million passengers flew nonstop in 2025, on 15 thousand flights of about 628 miles and 1.5 hours in the air. The average passenger accounted for about 91 kg of CO2 from the fuel burned, from 78 kg on Frontier Airlines to 97 kg on Southwest Airlines.

  • 91 kgCO2 per passenger, average
  • 628 milesabout 1.5 hours in the air
  • 2.0 millionpassengers in 2025
  • 77%of seats filled

CO2 per passenger, airline by airline

CO2 per passenger by airline, Denver to Las VegasBar chart of kilograms of CO2 per passenger on each airline between Denver and Las Vegas in 2025.0255075100Frontier Airlines78 kgUnited Airlines94 kgSouthwest Airlines97 kg
CO2 per passenger by airline, Denver to Las VegasBar chart of kilograms of CO2 per passenger on each airline between Denver and Las Vegas in 2025.050100Frontier Airlines78 kgUnited Airlines94 kgSouthwest Airlines97 kg
Kilograms of CO2 per passenger, one way, 2025. Fuel burned only. Less is better.
Denver to Las Vegas by airline, 2025
AirlineShare of passengersFlights (thousands)Main aircraftSeats per flightSeats filledkg CO2 per passenger
Southwest Airlines40%6.4Boeing 737 MAX 8, Boeing 737-70016575%97
United Airlines36%5.0Boeing 737-800, Boeing 737-900ER17979%94
Frontier Airlines25%3.1Airbus A320neo, Airbus A321neo20777%78

What explains the differences

It's number 70 of the 100 busiest city pairs by passengers, and number 37 for the lowest CO2 per mile flown (0.15 kg per passenger-mile, number 1 being the lowest). A typical route of 628 miles in this set comes out at about 106 kg, so this one is 14% below it.

The airlines on this route differ by 24% per passenger. Frontier Airlines burned 1,274 gallons per flight and 160 passengers on each, and Southwest Airlines 1,223 gallons and 123 passengers. The gap comes from how many passengers share each flight, not from fuel burned per flight. Frontier Airlines flew 77% full here against 75% for Southwest Airlines, flying mostly Airbus A320neo against Boeing 737 MAX 8.

For comparison, the EPA default factor for a flight of this length (0.129 kg per passenger-mile) would give 81 kg. The EPA figure is a national average for flights of that length. The measured figure for this route is 13% higher.

2019 compared with 2025

In 2019 the route carried 2.0 million passengers on 14 thousand flights. In 2025 it carried 2.0 million, down 0%, on 15 thousand flights, up 6%. The average flight had 169 seats then and 179 now, and 86% of them were filled against 77%.

CO2 per passenger was 88 kg in 2019 and 91 kg in 2025, up 3.9%. Fuel burned per flight was down 2.3% (1,314 gallons to 1,283) and passengers per flight were down 6.0% (146 to 137). The distance flown was about the same (628 miles then, 628 now).

Southwest Airlines led in both years, with 41% of passengers in 2019 and 40% in 2025. United Airlines gained the most share, 29% to 36%. Spirit Airlines no longer reaches 1% of passengers, having had 9% in 2019.

Airline by airline, Frontier Airlines went from 76 kg to 78 kg per passenger (198 seats per flight to 207, main aircraft Airbus A320neo in both years); Southwest Airlines went from 94 kg to 97 kg per passenger (153 seats per flight to 165, main aircraft Boeing 737-700 then and Boeing 737 MAX 8 now).

Denver to Las Vegas, 2019 and 2025
Measure20192025
Passengers (thousands)1,9891,988
Flights (thousands)13.614.5
Seats filled86%77%
Gallons of fuel per flight1,3141,283
kg CO2 per passenger8891
CO2 per passenger by airline, 2019 and 2025, Denver to Las VegasBar chart of kilograms of CO2 per passenger on Denver to Las Vegas for each major airline in 2019 and in 2025.0255075100Southwest Airlines 201994 kgSouthwest Airlines 202597 kgUnited Airlines 201992 kgUnited Airlines 202594 kgFrontier Airlines 201976 kgFrontier Airlines 202578 kg
CO2 per passenger by airline, 2019 and 2025, Denver to Las VegasBar chart of kilograms of CO2 per passenger on Denver to Las Vegas for each major airline in 2019 and in 2025.050100Southwest Airlines 201994 kgSouthwest Airlines 202597 kgUnited Airlines 201992 kgUnited Airlines 202594 kgFrontier Airlines 201976 kgFrontier Airlines 202578 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.

Denver to Las Vegas and back: time in the air

Flights from Denver to Las Vegas spent 91 minutes in the air on average in 2025, against 85 minutes from Las Vegas to Denver: 6 minutes longer, 7% more. That's the westbound direction, into the prevailing west-to-east winds, which at flight levels often blow at well over 50 miles an hour.

At this route's average burn of about 878 gallons per flight hour, those extra minutes cost about 92 gallons per flight, which is about 0.7 gallons or 7 kg of CO2 for each passenger on the slower direction. The route figure above averages both directions.

Time in the air by direction, 2025
DirectionAverage minutes in the airFlights
Denver to Las Vegas90.87,265
Las Vegas to Denver84.57,238

Fly or drive

Driving is about 735 miles by road, which we estimate as 1.17 times the straight-line distance. An average car emits about 218 kg of CO2 on the trip, at the EPA figure of 0.297 kg per vehicle-mile. Alone, that's 139% more than the 91 kg for a passenger on the flight.

With 3 people in the car, driving comes out lower per person than the flight (73 kg each, and 55 kg each for four). A larger SUV or pickup (0.394 kg per mile) would emit about 289 kg per vehicle.

CO2 per person by way of travel, Denver to Las VegasBar chart of kilograms of CO2 per person flying, driving or taking the train between Denver and Las Vegas.050100150200Flight, average91 kgCar, driver alone218 kgCar, 2 people109 kgCar, 4 people55 kg
CO2 per person by way of travel, Denver to Las VegasBar chart of kilograms of CO2 per person flying, driving or taking the train between Denver and Las Vegas.0100200Flight, average91 kgCar, driver alone218 kgCar, 2 people109 kgCar, 4 people55 kg
CO2 per person, Denver 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.

Routes with shared cities or nearby CO2 per mile

Los Angeles to Las Vegas53 kg CO2 per passenger over 227 milesLos Angeles to Denver130 kg CO2 per passenger over 850 milesSan Francisco to Las Vegas71 kg CO2 per passenger over 404 milesSan Francisco to Denver136 kg CO2 per passenger over 960 milesChicago to Houston134 kg CO2 per passenger over 928 milesChicago to Denver129 kg CO2 per passenger over 890 milesDallas-Fort Worth to Phoenix127 kg CO2 per passenger over 872 milesNew York to Miami158 kg CO2 per passenger over 1,082 miles

Airports on this route: Denver International Airport, Harry Reid International 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.