A checked bag goes in the hold; a carry-on travels in the cabin if it fits the operator’s allowance. Check which fare includes each item, then measure the bag and confirm prohibited contents.
Why the answer can change
Carry-on and personal item are separate categories. A gate check can change where the bag travels without making spare batteries acceptable in the hold.
Check your own trip
- Start with the airline flying each leg, the fare you bought, and the dates on your ticket.
- Count bags for each traveler. Measure the packed outside of every bag, then find both the standard limit and the largest bag the airline will accept.
- Look up the bag fee, extra-piece fee, and any weight or size charge separately. If one amount is missing, you don’t have a complete total yet.
- Check the final price in the airline’s booking or check-in flow, and save the receipt.
Before you pay
Use the size and fee tools to put your bag details in one place. If we can’t confirm the full cost, they’ll tell you what still needs an airline quote.
Where this gets tricky
A backpack can be a personal item on one fare and a paid carry-on on another if it does not fit the underseat box. Category and fare inclusion are separate checks.
Here’s what to check: Measure its outside dimensions, compare the operator’s cabin box, then decide whether to buy the cabin or checked product. Remove spare batteries if it is checked at the gate.
Before you rely on a price
| Check | Why it can change the answer |
|---|---|
| Ticket and fare | A policy can depend on when a ticket was issued or changed, and on the exact fare brand. |
| Bag and owner | Piece number, three outside dimensions and the traveler’s own benefits can alter the charge. |
| Official confirmation | The airline checkout or service desk decides final acceptance, taxes and payment. |
Official sources and evidence
- American Airlines: Carry-on bags and personal item sizes (official page read; checked 2026-10-31)
- FAA: Lithium batteries (official search excerpt; checked 2026-10-31)