The cheapest times to fly from DCA to USM are

  • February 12th to April 1st
  • April 16th to July 8th (except the weeks of April 23rd and June 25th)
  • October 8th to December 2nd

based on data collected exclusively by Champion Traveler across tens of millions of flights. Among all the dates above, the very cheapest time to fly from DCA to USM is mid May. Prices can be as high as $5142 for Saturday flights during early to mid August, or as low as $1469 for Wednesday flights around mid May.


When to Fly to Ko Samui

Flying from Washington, DC (DCA) to Koh Samui (USM) will usually cost between $1752 to $3430 per person if booking more than four weeks in advance. On average the very cheapest time to fly is mid May with an average ticket price of $1690. Due to high demand the most expensive time to fly is early to mid August, with an average price of $3525. Planning your trip to low-cost times can easily save you $1835 on economy flights and even more on first-class flights. Generally, any price below $2087 can be considered a good price for a round-trip DCA to USM flight.

See below for a graph of average weekly prices for the DCA to USM route. All prices are for round-trip tickets in USD.

DCA to USM Flight Prices

Compared to other flights, the DCA to USM flight is more expensive than the average and costs more than the average flight leaving from Washington. The average price per mile (for a direct flight) is $0.14, which is far below average.


Flight Prices by Day of the Week

Wednesday is usually the cheapest day to depart and return on this flight. Saturdays are the most expensive days to fly out or take a return trip. Selecting flights on the least expensive days could save you up to $815 (22%) on this flight.

Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Wednesday and returning a week later will cost an average of $2166. Return trip prices are from the USM to DCA flight, and often highlight the quality of our data in showing the same trend.

Departing Prices by Day

Departure Day Prices

Return Trip Prices by Day

Return Day Prices


Nonstop Flights and Layovers

Travelers looking to fly from DCA to USM can generally find a 2-layover flight. Because there is not usually a direct flight option the real-world direct flight time of 17 hour 20 minutes may not be realistic.


Flight Hacking DCA to USM

Flight hacking is when you book two tickets instead of a layover, sometimes with different airlines. You will need to either bring only a carry-on bag (highly recommended) or leave yourself plenty of time to go through security again. Flight hacking is completely allowed, but airlines don’t always tell you the cheapest way to get from DCA to USM — but Champion Traveler does!

Hack #1: Bangkok (DCA > BKK > USM)

  • Price for both tickets: $1106
  • Average savings: $981 (46.99%)

See DCA to BKK flights

Hack #2: Phuket (DCA > HKT > USM)

  • Price for both tickets: $1120
  • Average savings: $967 (46.32%)

See DCA to HKT flights

Hack #3: Chengdu (DCA > CTU > USM)

  • Price for both tickets: $1216
  • Average savings: $871 (41.72%)

See DCA to CTU flights


Flight Questions Answered

Still have questions about flying from DCA to USM? We’ve got answers.

Which airlines fly this route?

You can find 14 major airlines flying this route most often: Air Canada, Air France, American, Bangkok Airways, British Airways, Cathay Pacific, Delta, JAL, JetBlue, KLM, Malaysia Airlines, Qantas, Singapore Airlines, United, and potentially more during busy seasons.

How far away is it from Samui Airport to Ronald Reagan Washington National Airport?

The distance between the two airports is roughly 9086 miles or 14622 kilometers.

How long does it take to fly from DCA to USM?

The real-world flight time for a nonstop DCA to USM flight is about 17 hour 20 minutes.

How many flights go between Washington, DC and Koh Samui?

It depends on the day of the week and the date, but a typical day might have around 13 available flights from DCA to USM.


Airport Location Info


Departing Airport

Origination codeDCA
Origination airport nameRonald Reagan Washington National Airport
CityWashington, DC
Countrythe United States

Return Airport

Destination codeUSM
Destination airport nameSamui Airport
CityKoh Samui


Other Resources

Please note that while we’ve worked hard to analyzed tens of millions of flights to get you this data, we do not calculate current live prices or guarantee pricing. Please see our partners using the links above for current offers.