The age-old question in travel booking has always been whether to book two one-way flights or purchase a roundtrip ticket. Add the potential to book a multi-city itinerary, and now things are very confusing. Typically, people browse flights and book flights roundtrip. For domestic flights, the costs of two one-way flights will likely be the exact same as the roundtrip cost. However, there are scenarios, specifically when booking international flights, where booking one way can save you money. And what if you’re planning to visit multiple countries on one trip? Is it better to buy multi-city flights or one-way?
In this guide, we’ll help you save money on flights by helping you decide when to book a one-way, roundtrip, or multi-city flight.
Is it better to buy multi-city flights or one-way, or go for a roundtrip ticket?
The short answer: Whatever is cheapest.
We can and will discuss the intricacies of one-way vs. roundtrip, as well as when is it better to buy multi-city flights or one-way, but at the end of the day, you should book what is cheapest (assuming quality, experience, and convenience are more or less equal). More than likely, booking roundtrip will be more affordable, but there are many circumstances where booking multiple one-way flights or a multi-city itinerary could help you save money and/or time!
When to book a one-way
1. Most multi-city explorations
If you want to visit more than one city, is it better to buy multi-city flights or one-way? Booking a roundtrip flight will often not make sense. If you live in Miami and want to visit London, Rome, and Athens on your summer European trip, you wouldn’t want to book a roundtrip flight from Miami to London and have to fly back to London after Athens to get home. So, you’re left with two options:
- Book a multi-city itinerary.
- Book a bunch of one-ways.
In this scenario, is it better to buy multi-city flights or one-way? It likely makes more sense to book multiple one-way flights for convenience and savings, with one exception (read further).
Interestingly, international flights are often much cheaper roundtrip, so in this specific example in July 2025, booking a roundtrip flight from Miami to London and flying back to London from Athens is actually cheaper. But, for most, convenience outweighs importance and booking a one-way flight home from Athens makes more sense. The savings from the roundtrip flight were marginal anyway.
In this itinerary, the cost of a multi-city itinerary would be the same as booking multiple one-way flights, so either option works.
2. Price shopping between airlines
Different airlines often offer their best rates on different days or routes. By booking one-way flights, you can:
- Take advantage of airline-specific sales like Southwest’s Wednesday sales.
- Mix and match budget carriers with traditional airlines. Certain budget airlines like Allegiant Air only fly certain days of the week and can provide exceptional savings.
If you have some flexibility, you could save big by taking advantage of budget airlines.
The cheapest roundtrip flight option to fly from Indianapolis to Fort Myers, FL 4/8/25 – 4/11/25 is $416.
Allegiant Air, a budget airline, flies from IND to the nearby Punta Gorda airport (RSW). However, they do not fly that route on Tuesdays.
If you had the flexibility to fly out on Monday night instead of Tuesday morning, you could take advantage of this excellent one-way deal:
Then, you could purchase a one-way flight home on Friday with Delta.
Here, by utilizing budget airlines, being flexible with dates, and booking one-way, we saved $167.
3. One leg is inconvenient
Time is money. While you may not actually save cash doing this, booking two one-ways for more convenient flight times can be a very effective strategy. For example, let’s say you fly from the East to the West Coast on a Wednesday after taking advantage of a Southwest sale. The only flights home the next week are red-eyes with a connection. Even though it could be slightly more expensive, you could book a nonstop, one-way, daytime flight back to the East Coast to make your travel experience more comfortable.
When to book multi-city flights
Previously, I stated that booking one-way flights and a multi-city itinerary were the same price. That is generally true, except when this question comes into play:
Is it better to buy multi-city flights or one-way flights if the flights are in the same airline alliance?
If all of the flights are inside the same airline alliance, booking a multi-city itinerary can lead to significant savings.
Suppose you attempt to book a multi-city itinerary through Google Flights with airlines that are not in an alliance together. In that case, you will be directed to several travel sites to book each one-way flight individually.
However, when you piece together a multi-city itinerary that is operated by airlines in the same alliance, you can book an actual multi-city itinerary on one ticket through any of the airlines you’re flying with.
Let’s look at an example.
If you wanted to fly Chicago to Frankfurt, Frankfurt to London, and then London back to Chicago on United and Lufthansa (both Star Alliance airlines), the cost for a multi-city itinerary in June 2025 is $1,874.
If you were to book these flights one-way, Chicago to Frankfurt would be $1,593, Frankfurt to London would be $105, and London to Chicago would be $1,738.
In this example, you save $1,562 by booking a multi-city itinerary through United Airlines.
Also, you would only have one reservation instead of three, making travel details simpler.
If you’re planning a multi-city trip and need to determine is it better to buy multi-city flights or one-way flights, go to Google Flights and see if it’s cheaper to buy the cheapest one-way flights or to book a multi-city ticket with airlines inside the same alliance.
If you don’t know which alliance different airlines are in, this chart is a helpful reference:
When roundtrips are better
1. International long-haul flights
Traditional international carriers price roundtrip flights more attractively than two one-ways, especially for:
- Transcontinental routes
- Business class bookings
- Peak season travel
- Routes with limited competition
Let’s look at an example. To fly nonstop roundtrip on Lufthansa from Washington DC (IAD) to Frankfurt, Germany in July, the roundtrip price is $1,355. If you looked for the outbound flight one-way, the price is $1,048! The one-way inbound flight home is $1,827!
In this instance, by booking roundtrip, you would save $1,520. Even if you wanted to visit multiple cities in Europe, in this scenario, it would be most economical to book a roundtrip flight to Frankfurt and get a cheap flight from wherever you are in Europe back to Frankfurt.
2. Simplicity is important
Roundtrip tickets are easier to handle and typically offer better value when your travel dates are fixed and/or you’re flying between major hubs.
The example shared earlier about booking a one-way Allegiant flight to Florida to save money is not helpful if you don’t have a flexible schedule.
If you have fixed dates to fly, especially between major hubs where pricing is more fixed, booking roundtrip almost always makes more sense.
3. Points lovers
Roundtrip bookings are best for frequent flyer members because:
- They earn more miles or points.
- Upgrade opportunities might be better.
- Elite status benefits are easier to track.
- Minimum spending requirements are simpler to meet.
If you travel often and want to earn as many points as possible, sticking with one airline can be very helpful.
How to decide when is it better to buy multi-city flights, or one-way flights, or a roundtrip ticket
To find the best deal, follow these steps:
- Check all options
- Search for roundtrip flights first.
- Search for one-way options.
- If you’re going to multiple cities, check multi-city options (within the same airline alliance).
- Look at different departure dates (+/- 3 days).
- Consider other airports (like Punta Gorda vs. RSW).
- Factor in hidden costs
- Baggage fees (which might differ between airlines)
- Seat selection charges
- Airport transfer costs if using different airports (common in larger cities like New York or Paris)
- Consider timing
- Book at the best time.
- Use price trackers like Google Flights.
- Be flexible with travel dates.
Read also: How Far in Advance Should You Book a Flight?
Debunking some myths
- “Roundtrips are always cheaper.” This is often true, but with more low-cost carriers like Breeze, Allegiant, IcelandAir, and more offering competitive one-way pricing, there are plenty of scenarios where booking one-way can be cheaper.
- “One-way flights are always more expensive per leg.” This is not true. If you search domestic flights on major airlines between two hubs, the one-way prices will be almost identical to the roundtrip prices.
- “Budget airlines always offer the best one-way deals.” Not true! There are countless factors that determine airline ticket prices. Because of this, there are times when (thankfully) Delta is cheaper than Spirit.
Key takeaways
The choice between when is it better to buy multi-city flights, or one-way flights, or a roundtrip ticket depends on various factors:
- Your specific route
- Travel dates
- Airline options
- Flexibility needs
- Overall trip itinerary
It’s important to check both options for every trip. While roundtrip tickets might offer better value on certain routes (especially long-haul international flights), dynamically priced airline tickets mean one-way flights could be cheaper. In the right circumstances, a multi-city itinerary booked through an airline could be significantly cheaper than piecing together one-way flights.
Of course, the cheapest ticket isn’t always about the fare price. You have to consider the total cost, including baggage/seat fees. If a Spirit flight is $100 cheaper than a Southwest flight but you’re flying with three children, the Southwest flight will likely be cheaper due to high Spirit bag fees. Piecing together one-way trips can be difficult and confusing. Because of this, paying slightly more for a roundtrip or multi-city ticket might be worth it for the sake of simplicity.
