Cats are generally considered fully grown in terms of size and maturity anywhere between 12 to 18 months of age. Most cats reach adulthood at about 12 months, when their personalities mature and solidify. However, full physical growth can continue beyond this point. Some cats, especially larger breeds like Maine Coons, may not reach their full size until they are 2 to 4 years old. Female cats tend to stop growing earlier, usually around 10 to 12 months, while males may continue to grow closer to 18 months or longer. Growth also depends on factors such as breed, genetics, nutrition, and whether the cat is spayed or neutered. For example, smaller breeds may finish growing by 9 months, and larger breeds like Maine Coons can take several years to fully mature. Once a cat maintains the same height, length, and weight consistently for several months, it is likely fully grown. Veterinarians can also assess growth by examining bone development through physical exams or X-rays. In summary:
- Most cats reach adult size by 12 to 18 months.
- Large breeds may take up to 4 years to reach full size.
- Female cats typically mature faster than males.
- Growth varies by breed, genetics, nutrition, and spaying/neutering status.
