UPDATE: This Airfare Study has the most current information on the best time to buy flights.
It is a question that has been agonizing travelers for the last 30 years: when is the best time to buy an airline ticket? Buy too early and you feel like a sucker when the guy sitting next to you paid $100 less for buying his ticket three months later. Buy too late and…well, you might find yourself priced right out of the market.

when to buy airline ticket

Every year, when to buy a flight is the most frequently asked question our customer support team receives.  And every year, we crunch more and more data to try to find the best answer. In 2013, we monitored 4,191,533 trips. For each trip – that is, a flight from city A to city B on a specific date with a specific trip length– we looked at prospective fares over about a 10½ month booking window, ranging from 320 days in advance, to 1 day in advance, including every possible booking date in between. It adds up to a database of 1.3 billion air fares — and a serious headache for those who were tasked with making sense of it!

The simple answer is that in 2013 the best time to buy a domestic airline ticket was 54 days in advance, or 7 1/2 weeks on average. But before you send yourself a calendar invite 54 days before your next trip, read on; there is a lot more to the story.

The “Prime Booking Window”


For most domestic trips, we found a similar pattern. The worst time to book your trip was the last minute. No big shocker there. The day before was the single worst day, two days before was the second worst, etc. etc. all the way up to 13 days in advance. Our data completely debunks the myth that if you wait until the last minute, there will be big price reductions to take advantage of, as airlines dump empty seats. That simply doesn’t happen, and buying a flight with less than two weeks advance purchase is the last strategy we would recommend.

Besides not buying at least 14 days in advance, however, the next biggest mistake was usually to buy too early. On most airlines, flights open up for sale 331 days in advance. That is the earliest you can book a flight – about 11 months in advance. We found that for about four months from that time, domestic fares tended to stay pretty steady, and pretty high. That makes sense. Airlines just don’t get aggressive about offering fare sales for flights that far in advance. (Note, we are specifically referring to fares within the U.S. here. The pattern for international flights is different and we’ll discuss in a follow up post.)

According to the data, sometime around 225 days out (7 1/2 months), on average, fares started to drop and by 104 days out (3 1/2 months) they had fallen to within $10 of their low point. From there they continued to drop, slowly but steadily, until reaching a low 54 days before departure. After 54 days, fares started to climb again, remaining within $10 of that low until 29 days out. Then, the increase began to accelerate and once you were within 14 days the fares really shot up dramatically.

In short, between about one month out and three and a half months out (29 days to 104 days) fares were at their lowest point. We call this period the “prime booking window” where the average fare on each day was within $10 of the lowest fare possible. This is the period where 2013 domestic flights were generally the least expensive and this was usually the best time to buy.

What it All Means

Of course, that’s a pretty good sized window. On the surface, it may seem like we are saying as long as you don’t buy too early and don’t buy too late, you’ll be fine, so it’s not really that critical when you actually purchase your flight. But when we drill down on the numbers we see clearly that that is the wrong conclusion to draw. We keep saying “on average” because when you throw 4 million trips together, and run the numbers, the volatility tends to get smoothed out. But if you’re going to a specific destination, on a specific set of dates, general averages across the whole U.S. industry don’t matter – what really matters are prices for your exact trip. And here you’ll see that, if you look within the “prime booking window” at the individual trip level, there is a ton of volatility and fluctuation. We found that each individual trip had an average of 92 fare changes between the time fights opened for sale and the time they departed. For domestic flights, the average difference between buying a ticket on the best possible day to buy and the worst was $312! The smooth graph that you see above which is based on averages for all markets, would have a lot more spikes and valleys if it were drawn for just one trip, like we did here. The $312 difference between buying at the right time and the wrong time drives home the point that the decision of when to buy really does make a huge impact on what you end up paying.

So What Should You Do if You’re Planning a Trip?

We know this is a lot to digest, but here’s the bottom line:

It is less important to remember the 54 days number, and more important to understand that the market for each exact trip is so unique and so volatile that averages are not that meaningful. Unfortunately, there isn’t any silver bullet, best-time-to-buy, that you can mark in your calendar and not have to worry about. We constantly tell would-be flyers to search for flights early and often. As soon as you know you might be taking a trip, start checking fares. This doesn’t necessarily mean to buy early – in fact, most of the time we suggest waiting. But you want to become familiar with the market on your exact travel dates so you know what’s a good fare, what’s not, and what’s realistic. If you check back frequently, you will likely catch fares that are both on the high side and the low side, and you’ll have the right perspective to know which is which. Be ready, though. When you do see a good deal, you’ll want to grab it, as great fares don’t typically last for very long.

If you’re not confused enough, by now, please read our follow up post, “When to ignore our advice and book you air ticket as early as possible“.

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  1. This is a great article! It’s really helpful to know when the best time to buy airline tickets is. The data provided is really useful for those who want to save money on their travel. Thanks for sharing this knowledge!

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