Booking a flight involves navigating a maze of decisions. Is it better to fly with a budget airline or full-service one? How about basic economy versus regular economy? And would you prefer pretzels or a cookie? Choosing between a single round-trip or two one-way tickets is the most basic decision and — you might be surprised to learn — one of the more nuanced. The cost between the two is usually the same for domestic flights but can vary significantly for international routes. Given that airfare was 26% more expensive in January 2023 than January 2022, according to the latest consumer price index data, budget travelers need to save every penny they can. In general, it can be more convenient to book a round-trip flight for a trip with specific start and end dates, but other considerations, such as cancellation policies and pricing, could make booking one-ways more appealing in some cases.