Economist Makoto Watanabe worked out a formula designed to calculate the best time to buy an airline ticket if you’re looking for the lowest prices. The answer, according to his formula: eight weeks before your flight.
Like any such rule, I’m sure you’ll find plenty of exceptions, but if you don’t enjoy spending a lot of time agonizing about when to buy an airline ticket, it’s a good rule of thumb to have on hand. In addition to the eight-week rule, Watanabe’s formula also suggests that tickets are cheapest in the afternoon, according to The Observer. We can’t explain all the science to you [apparently the eight-week formula looks a little something like ∏A = gUG + min(k - g, (1 - g)(1 - r))], and the findings, which will be published in the Economic Journal, aren’t yet available.
If you’re not flexible enough to book right at the eight week point, consider fare prediction tools like Bing’s Farecast. You can plug in your travel dates and destinations, and it’ll give you its best-guess prediction as to whether you should expect a fare drop or increase, and offer a suggestion to help you decide if you should buy now or wait. We’ve also heard that Wednesday is the best day of the week to buy tickets, though not everyone agrees on that suggestion. Last, if you’re really serious about finding cheap airfare, check out Erica’s frequent flier guide to buying cheap airline tickets.