The recent case with an overweight cat denied Aeroflot boarding got me curious.

Aeroflot maintains a rule that a pet is only allowed onboard if it weighs 8 kg or less. This doesn't look like an arbitrary figure, but what is it derived from?

In fact, every airline seems to impose its own requirements for the weight of pets allowed to be checked in, ranging from 5 kg (Asiana) to 10 kg (Alitalia) to hardly any known particular limit (United). (I guess this caused some serious troubles somewhere in the world with connecting flights before) However, most of the limits are observed to be around 8-9 kg. Apparently, even trains in Japan have the same sort of limit even though those never take off the ground under normal conditions.

The pet weight requirement across airlines does not seem to match their respective hand luggage weight limits either. The aforementioned Aeroflot allows up to 15 kg of luggage in the business class seat where the cat's owner was flying. Also, e.g. Air France allows up to 12-18 kg of hand luggage but only 8 kg total of a cat.

Is this 8-9 kg figure a limitation of the aircraft (hence defined this way by Airbus and Boeing), an FAA/TSA requirement, regional laws, or what else?

  • 3
    I would think that the weight is an easier-to-enforce limit that is vaguely correlated to the size of the pet. A small pet which can easily fit in a bag which will in turn fit under the seat in front of you (a regular cat, a Yorkshire terrier, a chihuahua...) is not quite the same as a golden retriever, Bouvier Bernois or Irish wolfhound which will not fit anywhere. The exact limit is probably quite arbitrary. As the owner of an 11 kg dog, I definitely think that limit is completely arbitrary :-)
    – jcaron
    Nov 16, 2019 at 21:25
  • 2
    Also note that some airlines (especially UK-based airlines) don’t allow any pets onboard (not even in the hold).
    – jcaron
    Nov 16, 2019 at 21:26
  • 1
    There's a separate requirement on the size of the kennel. Yes, it must fit under the seat. Additionally, there's a weight limit which purpose I'm trying to understand. A limit of 10 kg (or 9 kg which is 20 lbs) is a nice round number which would've been likely to be arbitrary, but the number "8" doesn't look like that.
    – ximaera
    Nov 16, 2019 at 21:44
  • 1
    As a tangent, this cat's story provides an excellent example of how to sneak an overweight pet into an airplane :)
    – JonathanReez
    Nov 16, 2019 at 23:46
  • Some airlines allow “soft” bags and other holders, so the weight may be easier to enforce than the size. But it would also be interesting to compare those weight limits with those imposed on hang luggage, maybe there are the same (or were the same at some point and diverged since then)?
    – jcaron
    Nov 17, 2019 at 1:53

1 Answer 1


Obviously, airlines have to define some limitations, as they don't want you to bring your elephant with you.

Size limits are difficult to define and even harder to verify ('squeeze your doggy into this test frame please...'), and they want you and them to be easily able to handle the carrier. Therefore, they choose a weight limit that allows even non-bodybuilding stewardesses to lift it.

The exact number could of course be slightly different; 9 kg would probably have worked still, and 7.5 kg could also have been their choice. Every airline probably picks some number similar to others, as they don't want loose customers by being more restrictive, but they also don't want to get into problematic ranges.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .