Frontier Airlines has positioned itself as an a la carte airline, so you'll pay an upcharge for everything — including bags. Although you might find some incredibly low fares, Frontier baggage fees will significantly increase your trip's cost. So, despite low fares, the overall cost may not be affordable.

Frontier Airlines operates on an "unbundled" ultra-low-cost business model where the base fare covers only your transport and one small personal item. Because their ticket prices are often as low as $19, they generate the majority of their profit through ancillary fees, with baggage being the primary revenue driver. In 2026, Frontier's bag prices are dynamic—they are cheapest at the time of booking and become progressively more expensive the closer you get to the gate. A bag that costs $40 when you buy your ticket might cost $99 if you wait until the airport counter. Furthermore, Frontier has strict weight limits (often 40 lbs instead of the industry standard 50 lbs) and size restrictions that are rigorously enforced with sizing bins at the gate. These high fees subsidize the ultra-low ticket prices, essentially allowing passengers who travel with nothing but a backpack to fly for almost nothing, while those with luggage pay a premium that reflects the operational cost and profit margin of the airline.