Is it cheaper to book a round-trip or two one-way flights?

Generally, a round-trip on the same airline is cheaper. However, if you are flying long-haul, check if a multi-city flight (e.g., flying into Bangkok and out of Singapore) fits your itinerary to avoid backtracking costs.

Does it matter which airline I book?

If you are flying long-haul, stick to full-service carriers for better luggage allowances, as budget airlines add heavy fees for checked bags that can erase any savings.

How to Book Cheap Flights to Bangkok

Book your tickets 3 to 4 months in advance using Google Flights to track price drops. Avoid flying during the peak season from November to February to save at least $300 on your round-trip fare.

Set up price tracking alerts. Go to Google Flights, enter your departure city and Bangkok (BKK), and toggle the 'Track prices' switch. You will receive an email the moment the fare drops.
Use the flexible date calendar. Instead of selecting fixed dates, click the calendar icon in Google Flights. Look for the green-colored dates, which indicate the cheapest days to fly within that month.
Check alternative airports. Check fares for Don Mueang International Airport (DMK) alongside Suvarnabhumi (BKK). If you're coming from within Asia, low-cost carriers like AirAsia often serve DMK exclusively and are significantly cheaper.
Book mid-week. Flights departing on Tuesday or Wednesday are consistently $50–$100 cheaper than weekend departures. Avoid booking on a Friday or Sunday whenever possible.

Is it cheaper to book a round-trip or two one-way flights?: Generally, a round-trip on the same airline is cheaper. However, if you are flying long-haul, check if a multi-city flight (e.g., flying into Bangkok and out of Singapore) fits your itinerary to avoid backtracking costs.
Does it matter which airline I book?: If you are flying long-haul, stick to full-service carriers for better luggage allowances, as budget airlines add heavy fees for checked bags that can erase any savings.