Phoenix (PHX) to Denver (DEN): 601 miles (968 km) great-circle, about 1h 40m nonstop by our estimate. Cheapest fare observed: $49 round-trip on Frontier, nonstop, departing May 30, 2026.
$49 round-trip, Frontier F91376, departing 2026-05-30 at 05:15, returning 2026-05-30. The recorded itinerary left on a Saturday and came back the same day; the fare was observed 35 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $49, it was the cheapest of the 30 round-trip fares we recorded from PHX (median $231). That is 8.1 cents per great-circle mile (round-trip price over one-way distance), below the PHX median of 17.4 cents across 30 round-trip routes.
Routes from PHX of similar length: Sacramento (635 mi) at $212 and San Francisco (650 mi) at $254.
Frontier had the cheapest fare on 19 of 30 PHX routes. It is the 27th longest of the 30 routes we track from PHX.
Of 19 departure airports with a fare to Denver, Phoenix (PHX) ranked 1st at $49. Lowest: $49 from Phoenix (PHX); highest: $382 from Guadalajara (GDL); 10 nonstop. Cheapest-fare airlines (routes): Frontier (18) and Viva Aerobus (1).
The reverse, Denver (DEN) to Phoenix (PHX), was $48 round-trip on Frontier, nonstop, departing May 28, 2026. Denver to Phoenix flights.
Travelpayouts fares (cheapest per route, observed April 25, 2026); OurAirports coordinates and elevations; IANA zones America/Phoenix, America/Denver; flight time is our estimate.