Understanding Frontier Airlines Baggage Policy is essential for budget-conscious travelers. The airline allows one free personal item per passenger that must fit under the seat. Carry-ons and checked bags cost extra, with rates depending on when you purchase—cheaper online than at the gate. Bag size and weight restrictions are strictly enforced. Bags over 40 pounds or larger than 62 linear inches incur additional fees. Frontier’s a la carte pricing helps keep ticket prices low, but surprise baggage charges can add up fast. Plan ahead, measure your luggage, and prepay online to get the best value from Frontier’s baggage rules.