Frontier Airlines Personal Item Size: 18 x 14 x 8 Inches and 35 lb

Where these numbers come from

Frontier lets every passenger bring one personal item free, and it is the only free bag on the basic fare. The limit is 18 x 14 x 8 inches, measured with handles, wheels and straps, and it can weigh up to 35 lb. It has to fit under the seat in front of you. Frontier states that the size is checked during boarding.

The boarding check is where the fee risk sits. A bag that is too large is charged at the gate, when bag prices are at their highest. Reported carry-on prices at the gate reach $99 or more, compared with $30 to $60 at booking. Testing your bag before you leave home can save that difference on each direction of the trip.

The 35 lb weight limit is rarely the problem. The 8-inch depth is. A 14-inch wide, 18-inch tall backpack packed with a laptop, a jacket, shoes and a water bottle tends to bulge to 10 or 11 inches. Compression straps help, as does packing flat items against the back panel. Leave rigid items like shoes out, or wear them.

Worked example: a traveler on a two-way trip arrives with a bag of 18 x 14 x 10 inches. At the gate it fails and must be paid for as a carry-on. If the price is $99 each way, that is $198 on a fare that could have cost nothing in bags. Repacking to 18 x 14 x 8 would have saved the whole sum. Prepaying a carry-on at booking, in the $30 to $60 range, would have cost much less.

Frontier's policy notes that coats, canes, crutches, oxygen concentrators and other assistive devices are exempt from carry-on charges. The policy does not list other extras like diaper bags on the personal item page, so ask before travel if you rely on one. If the personal item alone does not work, the Economy bundle adds a 24 x 16 x 10 inch carry-on of up to 35 lb.

To measure, pack the bag, then measure length, width and depth on the outside edges, straps included. Use the does my bag fit finder for a pass or fail result. Then compare prices in Frontier baggage fees and cabin sizes in the Frontier baggage rules. American also uses the same 18 x 14 x 8 inch size.

Sources

• Frontier bag options
• DeepArrival: Frontier baggage fees

Figures checked on September 30, 2026.

This page is general information, not legal, insurance or travel-agent advice. Fees, rules and limits change, so confirm the figures with the official sources listed above before you book or travel.