Frequent-flier miles have gotten a bad reputation: easy to earn, hard to burn. But the truth is, finding an award seat actually got a little less difficult this year, according to a study by consulting agency IdeaWorks, which did trial runs on 24 frequent-flier programs worldwide by attempting to book award tickets on each for travel between June and October 2011. In the programs tested, availability rose to 68.6 percent, up from 66.1 in 2010. But your chances of snagging a free seat depend on which program you’re using. Low-fare airlines around the world scored best. Among the U.S. carriers, Southwest is the easiest to book on, with a 99.3 percent availability rate.

If you really want that award seat, you’re best off planning your trip nearly a year in advance, since that’s when most airlines open their award inventory, according to Banas. But spontaneous travelers shouldn’t despair: IdeaWorks’ study showed that U.S. legacy carriers’ springtime availability five to 15 days before a flight was nearly as good as (if not better than) when booking three to seven months in advance. Trying to determine the value of an award ticket?, an aggregator of various award programs, has a flight-search function that shows whether it’s better to pay the fare or book an award ticket, while shows side-by-side the price of any flight in cash or miles.

Airlines with the fewest available award seats, June–Oct. 2011
US Airways: 25.7%
Delta: 27.1%
AirTran: 47.1%
American: 62.9%
Alaska: 64.3%

By Travel + Leisure and Travel + Leisure Staff