Understanding Frontier personal item size guidelines is essential for a smooth travel experience. Frontier Airlines allows one free personal item per passenger, which must fit under the seat in front of you. The maximum dimensions for a personal item are 14" x 18" x 8" (including handles and wheels). Items exceeding this size may be considered a carry-on, requiring an additional fee. ... https://www.airlinereservationwindow.com/frontier-airlines-personal-item-size-limit/