One-Way vs. Round-Trip Flights: When Is It Worth Booking Separately?

Are round-trip flights cheaper? The short answer is that it depends. Where you’re traveling to and if you’re paying with cash or miles are the biggest factors in the equation.

For instance, if you’re traveling between the U.S. and Europe and paying in cash, it's cheaper to book a round-trip flight. But if you’re paying for that same flight with miles, the price of two one-way tickets will most often be the same as a round-trip flight (though the taxes paid may vary).

There are other considerations besides just price when comparing round-trip versus one-way flights. Travelers might be surprised to find that booking a round-trip award flight could lead to issues if you have a change in plans mid-trip.

Here's a look at options to weigh when booking round-trip versus one-way flights and answers to some frequently asked questions.

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When you book a round-trip flight, it means you travel from Destination A to Destination B and you return back to Destination A from Destination B. Both flights are booked as one ticket.

So when you’re purchasing the ticket, you select your origin, destination, departure and return date. You make one payment, whether it's with cash or miles.

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A one-way flight, in contrast, is a ticket booked with no return. So you’re only booking a flight from Destination A to Destination B. You can purchase a second, separate ticket from Destination B back to Destination A (should you so choose). One-way flights can be booked with cash or miles.

These types of flights are a good option for those who don’t know their return date, are only traveling in one direction or booking an open-jaw itinerary.

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When booking flights paid in cash, our recommendation is pretty simple: Book the option that's cheapest for your trip. If a round-trip flight is cheaper than two one-way flights, there's no reason to book two one-way flights.

If two one-way flights are the same price as a round-trip, it might make sense to book the one-way flight (as long as you don’t mind keeping track of the two separate reservations). Even though many airlines have eliminated change fees, it's much easier to change — or even cancel — a flight when there’s only one flight on the reservation to make a change to.

Sample flight within the U.S.

In this example flight search on American Airlines, booking two one-way tickets from Newark to Miami will cost $154 for the outgoing flight and $124 for the return, for a total of $278.

Outgoing flight

Return flight

If you were to book these two flights as a round-trip ticket, the price would be exactly the same at $278.

Sample international flight

It's a different ball game with international flights.

Take a look at this flight search from Washington-Dulles to Frankfurt, Germany, on United Airlines. If you were to book the flights as two one-way tickets, it would cost you $3,110.

Outgoing flight

Return flight

However, if you book these same flights as part of a round-trip ticket, you’d have to pay $1,783, representing a significant savings over booking two one-way flights.

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If you're planning on using points and miles to book award flights, you have a different set of factors to consider. In the case of award travel, it can make sense to book two one-way flights instead of a round-trip award.

Two one-way awards offer more flexibility

Most U.S. airlines have dropped change fees on both award and paid flights. So, if the price is the same, consider booking two one-way awards instead of a round-trip award to gain extra flexibility. Keep in mind that if you book a round trip, depending on the airline, you may have difficulty getting your miles redeposited if you need to change your award ticket after taking the first leg of the flight.

For example, if you cancel a United award flight midtrip, you'll retain the miles as a future flight credit. While the miles won't be refunded to your account, you'll have the chance to use them in the future.

Watch for higher taxes and fees when booking two one-way awards

When considering whether to book round-trip versus one-way awards, it's important to price out both options — particularly when flying overseas. Some airlines charge higher taxes and fees for awards that originate in certain regions of the world.

Delta SkyMiles is infamous for charging higher fees for award flights that originate in Europe. Also, particularly for international flights, Delta will often price round-trip award flights at less than the cost of two one-way awards.

For example, take a round-trip award from New York to Paris. Delta charges 50,000 SkyMiles plus $85 in taxes and fees for a round-trip main cabin award.

However, if you book the same flights as two one-way awards, you'll pay a total of 74,000 SkyMiles plus roughly $220 in taxes and fees. The outbound award costs 37,000 miles plus $6 in taxes and fees. Then, you'll need to pay another 37,000 SkyMiles plus around $220 to fly home.

In a situation like this, it makes sense to book a round-trip award. You'll save on miles and out-of-pocket costs.

Consider change fees on award flights

Most U.S. airlines have eliminated change fees on both paid flights and award tickets. However, that's not the case with all mileage programs. If you're booking through a mileage program that charges change fees, you may want to book a round-trip award to reduce the fees you could pay if you need to cancel the trip.

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Say you're considering flying to Europe to take a cruise from Budapest to Munich. One might assume that your only options are to:

1. Book a round-trip flight into one of the cities plus book a one-way intra-Europe flight between them.

2. Book two one-way flights — one-way into Budapest and one-way back from Munich.

However, there's a third option: booking an "open-jaw" flight. Many airlines will let you book a flight into Budapest and a flight back from Munich on the same ticket. Rather than pricing these flights as two one-way flights, the airline generally prices the flights similar to a round-trip.

» Learn more: The guide to open-jaw flights with Chase points

If you're using airline miles to book these flights, check to see if it's cheaper to book two one-way awards or an open-jaw award. As outlined in the Delta example above, award flights originating in Europe can have much higher taxes and fees. So it might make sense to book the two award segments together as a multicity award.