Personal Item Size Chart: Carry-On vs Underseat Bag by Airline

July 22, 2026

Quick Answer: A personal item is the smaller bag that must fit under the seat in front of you. It is separate from an overhead-bin carry-on, but its permitted size varies by airline. The safest move is to choose a soft-sided, compact bag and check the exact airline guide before every trip.

Reviewed July 22, 2026. Use the airline’s current policy for your booked flight.

Carry-on vs personal item: the practical difference

Bag	Where it goes	Best use
Carry-on	Overhead bin	Clothes, shoes, toiletries
Personal item	Under the seat	Documents, medication, laptop, chargers, in-flight essentials

Choose a bag that works under the seat

For a personal item, depth is often the limiting measurement. A flexible personal-item bag or underseat bag is usually easier to place than a rigid case. Pack the items you need during the flight nearest the top, and avoid filling every outside pocket.

Use the airline-specific guide—not a generic chart

There is no single personal-item measurement that applies to every carrier. Compare your bag against the airline that operates each flight:

Personal-item packing strategy

Keep passports, medication, keys, and electronics in the personal item.
Use a bag that can compress slightly instead of a bag that is rigid at the maximum size.
Put a change of clothes and essential toiletries inside for a delayed checked bag.
Do not assume a large backpack is a personal item just because it has shoulder straps.

When an underseat roller is risky

A small wheeled bag can be organized and convenient, but wheels reduce usable clearance under the seat. Check both its full exterior dimensions and the airline’s personal-item rule. If the itinerary uses more than one airline, use the strictest published limit.