As a result of Frontier baggage policy, these costs rise over time. Carry-on Procedure When traveling with a child, you are also permitted to bring a diaper bag together with your carry-on luggage. You can check a stroller and a car seat at the gate without paying anything. 18 x 14 x 8 inches for an individual (45.72 x 35.56 x 20.32 cm) Standard: no more than 35 pounds and 24 x 16 x 10 inches (60.96 x 40.64 x 25.4 cm) (15.88 kg). All checked luggage must not exceed 40 pounds (18 kg) in weight or 62 inches in length (158 cm). The cost listed below is for a single flight.