Cheapest day to book flights 

When it comes to the cheapest days to book flights, there’s no single rule that applies all the time. In fact, so many factors go into the cost of flights that it’s hard to know what the prices will be from one day to the next, let alone over the course of a year or on any given day of a single month.

That said, there are some recognizable patterns when you look at the costs for airfare over a long enough timeline, and some organizations have done studies to find out the cheapest day of the week to book flights. This includes Expedia’s 2024 Air Travel Hacks Report, which used actual flight data to help consumers decide on the most affordable times to book airfare or fly the friendly skies within the U.S. or overseas.

If you’re hoping to save on airfare this year and are curious about when you should book and which days of the week to fly, here's what to know. 

Cheapest day to book flights

So, what is the cheapest day of the week to book flights? In order to find out, Expedia used data compiled by the Airlines Reporting Corp., which has information on 15 billion flights across 490 airlines.

While the cheapest day to actually pay for airfare can vary from week to week, Expedia data shows consumers who book airfare on Sundays instead of Fridays tend to save approximately 5% on domestic and international economy class flights. For domestic business class flights, consumers can expect to save around 7%, and for international business class flights, consumers can expect to save around 24%.

Expedia also notes that Sunday was the cheapest day to book flights in 2021, 2022 and 2023, but savings rates have varied year to year.

If you want to save more, data from Expedia’s report shows you should book domestic flights at least a month in advance to save an average of 24% compared to those who booked last minute.

Meanwhile, booking international airfare around 60 days out tends to yield the best results, with Expedia data showing savings of around 10% for those who booked around that time. However, because average ticket prices peak around four months out from departure, they also recommend booking no earlier than four months out. This is a clear change from Expedia’s 2023 report, which recommended booking international flights around six months out from departure date.

Most affordable day of the week to travel

While booking your flight on a Sunday helps you get the lowest price, actually flying on a Thursday may help you save an average of 16% off airfare. Data shows that, almost across the board, travelers who flew on Thursdays instead of Sundays saved this much on both domestic and international flights.

However, consumers flying domestically can also see significant savings of around 13% if they fly out on Saturday instead of Sunday.

What factors impact flight prices?

A range of factors can impact the cost of flights, but most of it boils down to supply and demand. For example, costs for airfare tend to be less expensive during off-peak season to any destination, whereas prices surge during peak travel times when demand is higher, such as holidays and the summertime.

Fuel costs can also impact flight costs, along with the cost of labor, labor shortages and other underlying issues for airlines. Ultimately, airlines use complex algorithms to determine pricing for their fares, and these factors are just part of the equation.

Tips for finding cheap flights

To get the best deal on domestic or international airfare in 2024, you should:

—Book airfare on a Sunday. As previously mentioned, booking airfare on Sunday is cheaper than other days of the week, especially Fridays.

—Be willing to fly midweek. Since Thursdays tend to be the cheapest day to fly, see if you can tweak your travel plans so you depart and fly home during the week instead of on weekends.

—Set price alerts. Use a tool like the Hopper app to set up price alerts that notify you when airfare prices drop significantly or when their technology says it’s the cheapest day to book. Expedia also offers Price Drop Protection in their app for a fee or for free if you’re a Gold or Platinum tier One Key member. If you book a flight that becomes cheaper later on and you have Price Drop Protection, Expedia will refund you the difference.

—Avoid peak travel times. Not only can traveling off-peak help you score significant savings on airfare and hotels, but Expedia data shows that off-peak travel comes with fewer cancellations and delays overall. Booking early morning flights instead of afternoon flights will also make it less likely for you to see delays.

—Use companion passes. Companion passes vary from airline to airline but allow you to earn discounts on a flying companion’s ticket. Some of the best companion passes are offered by Southwest Airlines, American Airlines and British Airways.

—Earn airline miles. Consider signing up for frequent flyer programs that let you book airfare with miles you earn for flying and other activities. You can also start racking up miles for airfare with a co-branded airline credit card or travel credit card.