San Diego (SAN) to Chicago (CHI): 1,720 miles (2,768 km) great-circle, about 3h 55m nonstop by our estimate. Cheapest fare observed: $270 round-trip on Frontier, with 1 stop, departing June 12, 2026.
$270 round-trip, Frontier F91326, departing 2026-06-12 at 20:29, returning 2026-06-16. The recorded itinerary left on a Friday, returning on a Tuesday 4 nights later; the fare was observed 48 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $270, it ranked 14th of the 30 round-trip fares we recorded from SAN (median $279). That is 15.7 cents per great-circle mile (round-trip price over one-way distance), close to the SAN median of 15.0 cents across 30 round-trip routes.
Routes from SAN of similar length: Nashville (1,747 mi) at $358 and New Orleans (1,595 mi) at $240.
Frontier had the cheapest fare on 16 of 30 SAN routes. It is the 18th longest of the 30 routes we track from SAN.
Of 33 departure airports with a fare to Chicago, San Diego (SAN) ranked 24th at $270. Lowest: $89 from Atlanta (ATL); highest: $1241 from Nairobi (NBO); 16 nonstop. Cheapest-fare airlines (routes): Frontier (15), Spirit (5), United Airlines (4), American Airlines (2), airline 0O (1) and Alaska Airlines (1), plus 5 more.
Travelpayouts fares (cheapest per route, observed April 25, 2026); OurAirports coordinates and elevations; IANA zones America/Los_Angeles, America/Chicago; flight time is our estimate.