How Many Credit Card Miles Do You Need for a Free Flight?

You don't need a lot of miles to book a free flight.

Flying isn't cheap. The average U.S. airline fare is nearly $300, according to the U.S. Bureau of Labor Statistics. And if you're flying internationally, or you want to book premium seats, prices can easily exceed $1,000.

One of the best ways to cut your travel costs is with airline credit cards, which earn miles you can use for free airfare. For example, a card may offer 50,000 bonus miles for new cardholders who spend enough, as well as 2 miles per $1 on purchases. But it can be tricky to figure out how these miles translate into free flights. Is, say, 50,000 miles enough for one flight? Two? Here's the answer.

How many credit card miles you need for a free flight

A good rule of thumb is that you'll need 25,000 to 30,000 credit card miles for a round-trip economy fare within the United States.

That's not the absolute bare minimum. With most airlines, free flights generally start at 5,000 to 7,500 miles per one-way segment. So to book a round-trip flight, you typically need at least 10,000 to 15,000 miles. But prices that low tend to only be available on short hops, meaning flights of about an hour to an hour and a half. For anything longer, you'll need more miles.

In addition, there are several factors that can affect award airfare prices. And to make it more complicated, many airlines use dynamic award pricing. That means an award ticket's price in miles can change at a moment's notice.

The only way to know for sure how much a free flight will cost in miles is to search on the airline's website yourself. Even that will only be the current price, which could change. But to give you an idea of what to expect, here are the factors that matter most in terms of how many miles a flight costs.

Route

The route often has the biggest impact on award airfare prices. As mentioned earlier, if you're taking a short hop, like a flight from Los Angeles to Las Vegas, you could pay 5,000 to 7,500 miles each way. On the other hand, if you're flying across the country, it could cost 15,000 to 25,000 miles or more each way.

International airfare usually costs more in miles than domestic travel. It's not uncommon for these fares to cost 30,000 to 40,000 miles or more each way.

Fare class

Just like when you're paying in cash, fare class makes a big difference. If you want to fly in business class or first class, you'll need a lot more miles. For those premium travel classes, you can normally expect to pay at least 35,000 to 100,000 miles each way.

It can get even more expensive as well. Some airlines charge over 250,000 miles for first-class airfare during periods of high demand.

Another part of the fare class that matters is whether you book a "saver" or "anytime" award fare. Many airlines have these, although the exact name varies from airline to airline. Saver fares cost far fewer miles, but have limited availability. Anytime fares are easier to get, but they cost much more -- often double or triple the price of a saver fare.

Making the most of your miles

Because award ticket prices vary so much, how you use your miles is important. When you know how to get the most from them, you can maximize their value. Here's what makes the biggest difference:

• Start searching for flights as early as you can. Award tickets, and especially cheaper saver fares, get harder to find the closer your travel dates are. If you start shopping early, you're more likely to snag a saver fare and not need to use nearly as many miles.
• Try to be flexible about your travel dates. The more flexible you are, the easier it is to find deals. If you're willing to adjust your travel dates by a few days or even a week, that could help you pay much less.

One other thing to keep in mind is that miles tend to offer more value when you use them for premium airfare. A $400 economy fare may cost 30,000 miles, whereas a $3,000 business-class ticket may cost 60,000 miles. If you have an upcoming trip where you'd really like to fly in business class or first class, consider saving your miles for that and paying cash for cheaper fares.

Flying free of charge

It's not too hard to earn free flights with the right credit cards, as you don't need a ton of miles. This does depend on your travel habits, but there are often round-trip domestic fares available for 25,000 to 30,000 miles, and sometimes less. And since many airline cards offer sign-up bonuses, earning those miles gets easier. If you get a card offering 60,000 bonus miles, that welcome offer could cover two free flights for you.

Depending on how much you travel, you might not be able to pay for all your flights with miles. But if you use an airline card and maximize your rewards, you'll get at least some of them for free.