Personal item size limits on international flights

Direct answer: There isn’t a single international maximum size for personal items. The limit is defined by your airline, and usually by the operating carrier for each flight segment. A personal item must fit entirely under the seat; the exact external dimensions vary, so check your airline’s cabin-baggage page when you book and again before you pack Booking.com: How many carry-ons are allowed.

Personal item vs carry-on: the practical difference

Airlines distinguish a smaller under‑seat personal item (for things like a laptop, medications and documents) from a larger carry‑on that goes in the overhead bin. Many fares include both, but some lowest fares include only the under‑seat item. Always verify what your specific ticket permits Booking.com: How many carry-ons are allowed.

British Airways example, checked 25 October 2026

British Airways publishes an under‑seat personal bag allowance of up to 40 × 30 × 15 cm (16 × 12 × 6 in). This must fit easily under the seat in front of you. BA also lists a separate, larger cabin bag for the overhead bin with different dimensions British Airways baggage essentials.

How to confirm your exact limit for your flight

1. Identify the operating carrier for each segment in your itinerary. Codeshares often apply the operating airline’s cabin rules at boarding.
2. Open the carrier’s official cabin or baggage policy page for your route and fare. Look for a section labeled “personal item,” “under‑seat bag,” or “hand bag.”
3. Compare your bag’s external length × width × depth when fully packed to the listed numbers. If your trip mixes airlines, pack to the most restrictive limit.
4. When your fare includes only an under‑seat item, be ready to pay for or skip an overhead carry‑on if you need one.

Security screening vs airline size rules (jurisdiction matters)

Checkpoint security rules come from the relevant authorities. Airlines also impose carriage conditions, including additional battery restrictions, alongside their size and item-count limits. Check both sources. For instance, British Airways notes that power banks and spare batteries are not allowed in checked baggage and must be in hand baggage British Airways baggage essentials. If you travel with a power bank, confirm it rides in your cabin baggage and keep it in your personal item if your overhead bag might be gate‑checked. For battery specifics, see our guide: Is a 20,000 mAh power bank allowed in carry-on?

Measure and test-fit your personal item

Measure the fully packed bag on all three sides, including any bulging pockets. Many airlines expect dimensions to include protrusions like handles. A dining chair is not a model of an aircraft seat. Compare the fully packed bag with the published dimensions, and use the airline’s actual sizer where provided; do not use a generic household fit test as proof of acceptance. For step-by-step measuring, use: How to measure luggage size (including wheels).

Short FAQ

Is there an international standard size for personal items?

No. Each airline sets its own under‑seat dimensions. Always check the operating carrier’s page for your flight Booking.com: How many carry-ons are allowed.

What counts as a personal item?

Typically a smaller bag that fits completely under the seat, such as a purse, laptop bag or small backpack. Larger items intended for the overhead bin are treated as carry‑ons and follow different limits Booking.com: How many carry-ons are allowed.

Do international airlines weigh personal items?

Policies vary by carrier and route. Some airlines publish cabin-baggage weight limits and may check at the gate; others focus on dimensions. Check your airline’s page for your specific itinerary Booking.com: How many carry-ons are allowed.