How old is a 9-month-old kitten in human years?

≈ 11 human years.

Behaviour starts to settle, though a 9-month-old cat is still very much a teenager.

Kittens front-load their ageing: the first twelve months are worth about 15 human years, which is why a six-month-old kitten is closer to a human pre-teen than a toddler.

Nearby ages

6 months8 human years
7 months9 human years
8 months10 human years
9 months11 human years
10 months13 human years
11 months14 human years
12 months15 human years

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