The published distance
Suvarnabhumi Airport is 33 km from Marni BKK Hostel on this website's airport list. That is a straight distance, not a promise about traffic. Don Mueang, the other Bangkok airport, is closer at 17 km. Confirm which airport your ticket uses before you plan the ride.
Ways into the city
A taxi or ride-hailing car can go to the hostel door on Soi Worapong. Tell the driver Marni BKK Hostel, Wisutkasat Road, Ban Phan Thom — or Khaosan Road if they know the area better, then walk the last 500 m.
The Airport Rail Link runs between Suvarnabhumi and Phaya Thai. It does not stop at Khaosan Road. From Phaya Thai you still need a taxi, bus, or metro connection into Phra Nakhon. Fares and timetables change, so check them on the day.
Public buses also serve the airport. This site does not name a route number, because those change. The 24-hour front desk can help with local directions once you are in the neighborhood.
If you land early or late
Check-in starts at 2:00 PM and check-out is 12:00 PM. Luggage storage is available if you arrive first and want to walk to Khaosan Road without your bag. The hostel is in Phra Nakhon, so the airport ride and the walk to the street are the same arrival, not two separate trips across Bangkok.
Compare beds on the rooms page or check availability before you fly.
Stay in Phra Nakhon
Marni BKK Hostel is the base these notes are written from. Check dorms and private rooms for your dates.