If you're looking to find the best deal on airfare, there are more tools out there to help you than ever before. Travel sites allow users to compare ticket prices based on airlines and the dates of their trip, but the numbers they show don't always paint the full picture. Additional fees for baggage can make a flight that seemed like a steal at booking suddenly a lot less convenient. Fortunately for frugal flyers, KAYAK has found a way to work this factor into their equations, Travel + Leisure reports.

To use the fare search engine's new baggage fee feature, start by entering the information for your flight like you normally would. Flying from New York to Chicago and back the first week of May? KAYAK recommends taking Spirit Airlines if you're looking to pay as little as possible.

But let's say you plan on checking two bags on your flight—different airlines charge different baggage fees, so Spirit may no longer be the cheapest option. If that's the case, KAYAK includes a Fee Assistant bar right above the search results. After entering the number of carry-on and checked bags you'll be traveling with, the results will automatically update to show the true cost of your fare. Ticket prices for New York to Chicago rise across the board with the addition of two checked bags, and Delta now becomes the best deal if you're looking to book through one airline.

The new baggage fee assistant is one way for travelers to make savvier purchases when booking online. But even with the added fees included, you'll need to do some extra research to determine the true value you get from each ticket price that pops up. Wi-Fi, legroom, and in-flight meal quality are all factors that could make a slightly more expensive airline worth it once you board.

[h/t Travel + Leisure]