Philadelphia (PHL) to San Juan (SJU): 1,580 miles (2,543 km) great-circle, about 3h 40m nonstop by our estimate. Cheapest fare observed: $134 round-trip on Frontier, with 1 stop, departing July 25, 2026.
$134 round-trip, Frontier F91541, departing 2026-07-25 at 21:16, returning 2026-07-30. The recorded itinerary left on a Saturday, returning on a Thursday 5 nights later; the fare was observed 91 days before departure. "Book this flight" opens Kiwi.com with the same airline and dates.
At $134, it ranked 5th of the 30 round-trip fares we recorded from PHL (median $234). That is 8.5 cents per great-circle mile (round-trip price over one-way distance), below the PHL median of 21.3 cents across 30 round-trip routes.
Routes from PHL of similar length: Denver (1,554 mi) at $216 and Punta Cana (1,528 mi) at $407.
Frontier had the cheapest fare on 19 of 30 PHL routes. It is the 11th longest of the 30 routes we track from PHL.
Of 20 departure airports with a fare to San Juan, Philadelphia (PHL) ranked 2nd at $134. Lowest: $127 from Orlando (MCO); highest: $632 from Washington DC (IAD); 7 nonstop. Cheapest-fare airlines (routes): Frontier (9), Spirit (4), American Airlines (2), JetBlue (2), Southwest (1) and United Airlines (1), plus 1 more.
Travelpayouts fares (cheapest per route, observed April 25, 2026); OurAirports coordinates and elevations; IANA zones America/New_York, America/Puerto_Rico; flight time is our estimate.