when do cats become adults? Comprehensive guide

Cat teenage years

Cats, like humans, go through various stages of development before reaching adulthood. One of these stages is their teenage years. During this time, cats experience significant physical and behavioral changes as they transition from cute little kittens into fully grown adult cats.

When are cats adults

when do cats become adults

Determining when cats become adults is not an exact science, as it can vary depending on several factors such as breed, size, and overall health. However, on average, most cats are considered adults between the ages of one and two years old. It is during this time that cats reach their physical and sexual maturity.

Cat developmental stages

Understanding the different developmental stages of cats can help cat owners provide appropriate care and guidance to their feline companions. From birth to adulthood, cats go through several key stages of development:

Birth to two weeks old: The neonatal stage

During this stage, kittens are completely dependent on their mother for nourishment and warmth. They are born with their eyes closed and their ears folded, and their primary focus is on feeding and growing. They rely on their mother's milk for nutrition and will double their birth weight within the first week.

Two to four weeks old: The transitional stage

At around two weeks of age, kittens' eyes begin to open, and they start to explore their surroundings. They also start weaning off their mother's milk and transitioning to solid food. During this stage, kittens become more coordinated and start developing their social skills through play and interaction with their littermates.

Four to eight weeks old: The socialization stage

During this stage, kittens continue to grow and develop physically. They become more active and adventurous, exploring their environment with curiosity. This is a critical period for socialization, where kittens learn to interact with humans and other animals. Positive experiences during this stage can contribute to their overall behavior and temperament in adulthood.

Eight weeks to one year old: The juvenile stage

This stage is often referred to as the "teenage years" for cats. During this time, kittens experience rapid growth and physical changes, including the development of their reproductive organs. They may also exhibit more independent and exploratory behaviors, as they gradually become less reliant on their mother. It is important to provide proper nutrition and regular veterinary care during this period to support their healthy growth.

One to two years old: Young adulthood

By the time cats reach one to two years old, they are considered young adults. They have reached their full size and have developed sexually. Cats at this stage are generally more settled in their behaviors and may exhibit more consistent patterns of activity and rest. They are still playful and energetic but have transitioned into their adult personalities.

Cat growth and development

Cat growth and development are influenced by various factors, including genetics, nutrition, and overall health. While there is no exact timeline for each cat's growth, a general overview of the stages can help cat owners monitor their cat's progress and ensure they are meeting their developmental milestones:

Birth to five days old

During the first few days of life, kittens rely entirely on their mother for nourishment and warmth. They spend most of their time sleeping and feeding.

One week old

Kittens' eyes are closed, and their ears are folded. They are still completely reliant on their mother for care.

Two weeks old

Kittens' eyes begin to open, and they start to become more aware of their surroundings. They may attempt to wobble around and explore their immediate environment.

Three weeks old

Kittens' eyes are fully open, and their vision is becoming clearer. They begin to coordinate their movements better and may start attempting to play with their littermates.

Four weeks old

Kittens start developing their baby teeth and may begin nibbling on soft solid food in addition to nursing. They become more active and playful with their littermates.

Six to seven weeks old

Kittens are fully weaned from their mother's milk and rely on solid food for nutrition. They become more independent and may start exploring their environment with increased confidence.

Eight to twelve weeks old

Kittens continue to grow rapidly and develop their coordination and physical abilities. They are highly curious and playful, learning important social skills through interactions with humans and other animals.

Three to six months old

Kittens' growth slows down, but they may still experience occasional growth spurts. They may start losing their baby teeth, and their permanent teeth begin to emerge. They become more sexually mature.

Six months to one year old

Kittens transition into young adulthood during this period. They have reached their full size and sexual maturity. Their behaviors may stabilize, and they begin to show more consistency in their daily routines.

One year old and beyond

Once cats reach one year old, they are considered adults. They have fully developed physically and sexually. However, just like humans, cats can continue to mature emotionally and behaviorally as they navigate through life.

Cat life cycle stages

The life cycle of a cat consists of several distinct stages, each with its own milestones and characteristics:


From birth to around one year old, cats are considered kittens. This is a period of rapid growth and development, both physically and behaviorally. Kittens are highly energetic, playful, and curious as they explore the world around them.


From around one year old to around eight years old, cats are considered adults. They have reached their full size and physical maturity. Adult cats tend to be more settled in their behaviors and may exhibit less playful and exploratory behaviors compared to kittens.

Mature adulthood

From around eight years old to around twelve years old, cats enter the mature adulthood stage. While still physically capable, cats at this stage may start to show signs of aging, such as decreased activity levels and potential age-related health issues.

Senior years

Cats entering their senior years, typically around twelve years old and beyond, may require additional care and attention. They may experience more age-related health issues and may benefit from a specially tailored diet and regular veterinary check-ups.

When do cats become adults

Cats become adults between the ages of one and two years old. However, it's important to note that individual cats may mature at slightly different rates. Factors such as breed, size, and overall health can influence the timing of reaching adulthood. It's always a good idea to consult with a veterinarian to assess your specific cat's development and ensure they are receiving appropriate care.

Cat maturity timeline

The timeline for cat maturity can vary based on the aforementioned factors:

Birth to four weeks old

Kittens are in the neonatal stage and rely completely on their mother for care.

Four to eight weeks old

Kittens transition into the socialization stage and start exploring their environment.

Eight weeks to one year old

Cats go through their juvenile stage, experiencing rapid growth and development.

One to two years old

Cats reach young adulthood and are considered fully grown and sexually mature.


Understanding the various stages of cat development and when cats become adults can help cat owners provide appropriate care, nutrition, and socialization to their feline companions. While the specific timeline may vary, most cats reach adulthood between the ages of one and two years old. It's important to remember that cats, like humans, are individuals, and their growth and maturity can be influenced by various factors. By observing their cat's behaviors and consulting with a veterinarian, cat owners can ensure their furry friends thrive throughout each stage of their life cycle.