Denver (DEN) to San Francisco (SFO): 965 miles (1,553 km) great-circle, about 2h 25m nonstop by our estimate. Cheapest fare observed: $159 round-trip on Frontier, with 1 stop, departing May 14, 2026.
$159 round-trip, Frontier F92141, departing 2026-05-14 at 09:03, returning 2026-05-18. The recorded itinerary left on a Thursday, returning on a Monday 4 nights later; the fare was observed 19 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $159, it ranked 7th of the 30 round-trip fares we recorded from DEN (median $204). That is 16.5 cents per great-circle mile (round-trip price over one-way distance), close to the DEN median of 16.1 cents across 30 round-trip routes.
Routes from DEN of similar length: Portland (989 mi) at $97 and Louisville (1,021 mi) at $328.
Frontier had the cheapest fare on 19 of 30 DEN routes. It is the 21st longest of the 30 routes we track from DEN.
Of 19 departure airports with a fare to San Francisco, Denver (DEN) ranked 3rd at $159. Lowest: $126 from Los Angeles (LAX); highest: $483 from New York (JFK); 6 nonstop. Cheapest-fare airlines (routes): Frontier (13), Southwest (3), American Airlines (1), United Airlines (1) and WestJet (1).
Travelpayouts fares (cheapest per route, observed April 25, 2026); OurAirports coordinates and elevations; IANA zones America/Denver, America/Los_Angeles; flight time is our estimate.