If you’ve booked a flight on Spirit Airlines recently, you may have been thrilled at the cost of the airfare — but there’s no doubt that a little sticker shock set in when realizing how many additional fees the airline charges.

This is the case for seat selection, priority boarding, printing out a boarding pass and even bringing a carry-on bag.

If you’re looking to bring luggage with you on your flight, you may be wondering how Spirit’s baggage fees work, how much they cost and how to avoid paying them.

Spirit baggage fees: The basics

When it comes to the types of baggage included with your ticket on Spirit Airlines, there’s not much to say. One personal item can be brought for free, but a carry-on bag or a checked bag will cost extra.

Bag prices for Spirit aren’t especially transparent. Rather than having one dedicated chart, Spirit’s website directs you to its baggage calculator, called the Bag-O-Tron, where you can research the cost of bringing a bag for your flight.