The cheapest way to the airport. Nothing listed is quicker.
M4 metro to Kadıköy
M4 · Metro İstanbul, fare set by İBBPickup, hours & luggage
Boards at. Kadıköy metro station, the M4's first stop
TRY 46.20 on an İstanbulkart, the flat first-boarding fare. A bank card or phone tapped on the gate, or a single-use ticket, pays TRY 65. Children pay from age seven; there is no group ticket. Changing to the Marmaray or a bus on the same card is a TRY 34.40 transfer, not a second full fare. Between 00:30 and 05:30 on Friday and Saturday nights every fare doubles.
Luggage. One large suitcase, up to 30 kg and 120 x 60 x 50 cm, plus a cabin bag or small backpack, free. A second suitcase costs one more fare. Ordinary metro cars without racks.
Hours. Every day, every 4 to 10 minutes; 52 minutes to the airport, the last stop. On Friday and Saturday nights trains keep going every 30 minutes from 00:30 to 05:30 at double fare.