Exactly When to Book Flights to Get the Cheapest Price

Buying plane tickets
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When it comes to super useful travel knowledge, nothing tops knowing when to book your flights.

The booking site CheapAir.com recently crunched the numbers on nearly three million trips in more than 8,000 markets for fares booked between one and 335 days in advance. After analyzing 1.3 billion airfares, the CheapAir team found that the best fares were snagged booking, on average, 54 days in advance for domestic flights.

Airfares are determined using a surge pricing model, which means they are based on supply and demand and can fluctuate significantly from week to week. As you move from the time a flight initially opens for sale about 11 months out, to the day the flight departs, there is a pattern of how fares change—typically starting off high, slowly coming down, and then a few weeks before flight time starting to climb, with a particularly sharp increase once you’re inside 14 days.

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To make this easier to understand, CheapAir divided the typical booking window of a flight into five booking “zones” labeled “First Dibs” (6.5–11 months out); “Peace of Mind” (3.5–6.5 months out); the “Prime Booking Window” (3 weeks–3.5 months out); the “Push Your Luck” (14–20 days out); and “Hail Mary” (0–13 days out).

The “First Dibs” Zone
197-335 days out (approximately 6.5-11 months)
Most airlines begin selling seats for flights 335 days out, or roughly 11 months in advance.

In most cases, fares are on the high side and will likely to come down in the future. The big advantage to buying flights early is that you have a full choice of flight options and better seat selection. The lowest fares at this time average about $50 higher than during the “Prime Booking Window."

The “Peace of Mind” Zone
113-196 days out (approximately 3.5-6.5 months)
Want to relax and know your plans are firm well in advance of your trip?

The “Peace of Mind” Zone might be for you. Travelers booking in this window pay a modest premium of $20 more, on average, than the those buying in the “Prime Booking Window." You stil have more flight options and better seat selection than those buying closer in.

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The “Prime Booking Window”
21-112 days out (approximately 3 weeks-3.5 months)
When it comes to price, the sweet spot is the “Prime Booking Window”, about 3 weeks to 3.5 months in advance. The trick is to monitor fares during these 90 days, since fares will likely fluctuate a lot. Don’t be surprised to see big swings, sometimes from day to day. At some point during these 3 months the best fare is likely to pop up.

The “Push Your Luck” Zone
14-20 days out (2-3 weeks)
An interesting dynamic occurs in the week betwen three weeks out and two weeks out. If you’re thinking about wiating until this window, recognize that you are chancing it. In general, the more popular your destination and the more popular your travel time, the less likely you are get lucky since full flights are expensive flights. Going to Orlando for spring break? There's virtually no chance of scoring a good deal this late in the game.

The “Hail Mary” Zone
0-13 days out
The overwhelming majority of last-minute fare searches end in frustration. When you book your flight within 7 days of departure, you pay, on average, just under $200 more than if you booked during the “Prime Booking” window. In addition, you’ll probably have few choices for flight time. When you book between 7 and 13 days out, you can still expect at least a $75 premium on the cheapest flight, and often hundreds of dollars more on the best flights.

Key Take-Aways From the Study

  • Booking very far ahead—almost a year out—will not get you the best price.
  • The "prime booking window" is three weeks to 3.5 months out. On average, the best day is 54 days out.
  • You'll pay much more if you wait unitl the last minute to book your flights. Airfares tend to skyrocket two weeks in advance of a domestic trip, so if you want to nab the best price, do it before then.
  • CheapAir.com's study found that the average price difference between buying on the “best” day versus buying on the “worst” was $212 per ticket—or almost $850 for a family of four.

International Flights

For international flights, the ideal booking window is considerably earlier. A CheapAir.com study in 2014 found that the best time to buy cheap airline tickets to Latin America averaged out to 96 days in advance. For the Caribbean, it was 144 days, or almost five months ahead. For flights to Europe it was 276 days, or about nine months in advance. For Asia was 318 days, or about 10 months out.

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