This is such a wide-open question as to be almost meaningless. The weight of a cat depends upon its species, its gender, whether they are obese or anorexic and where they live. Have you seen the slender Mediterranean cats? And there is an obesity epidemic among domestic cats and people! This affects the average weight dramatically. Perhaps the question should ask for the ideal weight but I am going to present what I believe is the current average.
I’ll presume that the title is a question about the average weight of the domestic cat. That is the most likely reason why Google finds this search term. People are searching for the average weight of a cat perhaps to answer a question that they have which is whether their cat is over or underweight.
I took my cat to the vet yesterday. He is a classic, standard, male tabby cat. The vet said that he was an ideal weight. He is neither large or small. His weight was measured at 5.5 kg which is 12 lbs. I’m going to state with some confidence that the average weight of a male domestic cat in 2021 is around 12 lbs. I would estimate females to be around 10 pounds on average. An overall average might be 11 pounds.
I think that you will find that this is heavier than the weights quoted in reference books which are 10-20 years old. I’ve read that the average weight of the domestic cat is around 10 pounds from these reference books. I have even seen a number as low as 8 pounds. These appear to be out of date. They are getting bigger!
I ran a poll about 12 years ago on a page about the largest domestic cat breed. The poll asks the public the weight of their cat. You can see the results below. The most likely weight would be what I described as biggish in the 12-18 lbs range. This supports my assessment that the average weight of a cat is around 12 pounds. However, these statistics may be distorted by the fact that most of the respondents using the poll live in the US where the cats are bigger! Perhaps some are overweight.
As mentioned, there will be a slight difference between male and females and therefore this number is an average. And my cat is male. But I still think about 10-12 pounds is a fair average weight of a domestic cat nowadays.
As for the wild cat species, you can’t average them because their weights vary enormously between the tiny rusty-spotted cat and the enormous tiger. The rusty-spotted cat is smaller than the regular domestic cat. It is, in fact, the smallest cat on the planet in terms of its expected size. The largest cat is the Siberian tiger. And artificially, the largest cat of all would be a hybrid between the tiger and the lion, a liger. This is because of hybrid vigour although I’ve seen one which is overweight which doesn’t help.
SOME MORE ON CAT WEIGHT: