Growing up Fast: How Long Do Cats Stay “Kittens?”

Updated: September 18, 2023


Determining when a cat reaches puberty is a nuanced matter, contingent upon its breed. Typically, felines enter this phase around 6 or 7 months, yet outliers exist, with some experiencing it at tender ages of 4 months, while others delay until a mature 10 months.

Defining a kitten itself presents an intriguing challenge. While the majority, including cat food manufacturers, categorize a kitten as a juvenile cat under a year, veterinarians employ a distinct “life stage” framework. For them, a kitten is a youthful cat that hasn’t yet entered puberty, typically around six months of age. Junior cats mirror the teenage phase, characterized by rapid growth and boundless energy. Prime and mature cats signify young and middle-aged adulthood, respectively. The senior and geriatric labels encompass the elderly feline population.

Generally, cats boast a life expectancy of 15 years, although this span can fluctuate based on the breed. Remarkably, certain breeds, such as the American Shorthair, can thrive for up to two decades, underscoring the intricate tapestry of feline life cycles.

How Fast Do Kittens Grow?

A newborn kitten enters the world weighing just a few ounces. With proper nourishment, she can gain between ¼ to ½ an ounce each day, effectively doubling her weight by the time she reaches two weeks of age. Over her inaugural year, a healthy kitten should generally put on about a pound per month. By the time they reach six months, most cats will have achieved roughly ½ to ¾ of their eventual adult weight, typically ranging between six to eight pounds.

The ultimate size of a kitten is influenced by factors like breed, gender, and overall health. It’s a well-known fact that female cats are generally smaller than their male counterparts. Small breeds like the Munchkin often experience a deceleration in growth between six to eight months of age, with fully grown Munchkins weighing in at a range of five to nine pounds.

On the opposite end of the spectrum, large breeds such as the Maine Coon can continue growing for an astonishing four to five years. This majestic feline holds the title for the largest domestic cat, with adult males stretching up to four feet in length, from nose to tail, and tipping the scales at over 25 pounds.

Remarkably, in specific breeds like the Maine Coon, a kitten’s gender influences the timing of sexual maturity. Female kittens, for instance, do not experience their first heat until they reach approximately 5.5 pounds, typically occurring between four to six months of age. In contrast, male kittens don’t commence territorial marking or spraying until they hit ten months.

When Should Someone Get a Kitten Fixed?

Traditionally, veterinarians advised spaying or neutering kittens at the age of six months. However, this practice posed a significant risk, as some cats could reach sexual maturity as early as four months, potentially leading to unintended litters before reaching the recommended age for the procedure.

In modern times, the veterinary consensus has shifted towards advocating for early spaying or neutering, with some practitioners willing to perform the surgery on kittens as young as six weeks, provided they meet certain size and health criteria. The primary criterion is that the kitten must weigh at least two pounds before undergoing spaying or neutering.

This updated approach to early spaying or neutering offers several benefits. First and foremost, it greatly reduces the risk of unplanned pregnancies, curbing the overpopulation problem that shelters and rescues often grapple with. Additionally, early spaying and neutering can help deter undesirable behaviors like spraying in cats, promoting a more harmonious and manageable living environment for both pets and their owners.

By prioritizing early intervention when it comes to spaying and neutering, veterinarians contribute to healthier and more responsible pet ownership, preventing unwanted litters and behavioral issues while ensuring the welfare of feline companions.

What Is a Perma-Kitten?

A perma-kitten refers to a cat that maintains kitten-like characteristics well into adulthood. One of the most renowned examples is the internet sensation, Lil Bub, who is often described as a perma-kitten due to her oversized head and short limbs reminiscent of a kitten. Born in 2011, Lil Bub possesses a severe form of dwarfism known as achondroplasia, resulting in her petite stature and disproportionate physique. Additionally, she grapples with various health issues including osteoporosis and an underdeveloped lower jaw.

Certain cat breeds, like the Munchkin and Singapura, also exhibit a perpetually kittenish appearance, primarily due to their diminutive size. The Munchkin, akin to a feline counterpart of a dachshund, features extraordinarily short legs while maintaining proportionate head and body dimensions, distinct from Lil Bub’s achondroplasia. While some Munchkin cats enjoy good health, others contend with skeletal concerns like osteoarthritis or a spine curvature condition termed lordosis.

The Singapura garners distinction as the world’s smallest domestic cat, with females weighing as little as four pounds and “larger” males reaching twice that weight. They consistently sport a beige coat color referred to as “sepia,” characterized by a ticked pattern akin to that of a cougar.

Unfortunately, the Singapura breed often grapples with uterine inertia, a condition where the uterine muscles lack the strength to facilitate natural kitten delivery. Consequently, many Singapuras necessitate Caesarean sections during the birthing process.

A recently developed cat breed originating in Russia during the 1980s. It surpasses even the Singapura in compactness, with adult cats resembling the size of four-month-old kittens. Toybobs present a diverse array of coat colors, although a majority exhibit pointed patterns akin to the Siamese. Advocates of this breed contend that Toybobs are not only robust and intelligent but also exceptionally playful.

Factors That Affect Kitten Growth

Determining when your cat has reached full maturity isn’t solely reliant on age and weight; individual factors play a significant role. Gender, breed, and neutering can all influence the pace at which your kitten develops into an adult cat.


Diverse cat breeds vary greatly in size compared to the typical household cat. For instance, breeds like Siamese, Sphynx, and Khao Manee tend to have lower body weights, often achieving their full size earlier. Conversely, larger breeds like Maine Coons can tip the scales at 25 pounds or more. Due to their substantial size, these breeds require a minimum of two to three years to reach full adulthood.

For accurate guidance, consult your veterinarian regarding the anticipated adult weight for your cat’s specific breed. This knowledge will help you discern when the transition from kitten to adult food is appropriate.


As in many species, male cats generally have larger frames than their female counterparts. This means that the average male cat may weigh around 14 pounds. “Male cats are usually 10- to 15-percent larger,” notes Demos. However, exceptions do exist, as some female cats can also be quite sizable.


Neutering plays a crucial role in a male kitten’s growth trajectory. This procedure eliminates the influence of certain hormones crucial to the growth process. If carried out prematurely, neutering can abruptly halt the growth cycle.

“If possible, I recommend waiting until your male kitten is around five or six months old before proceeding with the procedure,” advises Demos. This is primarily because the urethra—the tube responsible for transporting urine from the bladder—will continue to develop if neutering isn’t performed too early.

For female cats, the timing of spaying doesn’t seem to have the same impact on growth.

Kittenhood is a fleeting phase, so be sure to keep your camera handy to capture those adorable moments. While your cat’s physical growth will eventually plateau, her inquisitiveness and enthusiasm for life (and naps) will endure.

What Happens as a Kitten Grows Up?

Kittens enter the world in a state of complete vulnerability. Blind, deaf, and with limited mobility, they rely entirely on their mother for care. Over the course of their initial two weeks, often referred to as the neonatal period, their senses gradually awaken. Responding to sound becomes one of their earliest developments, and their eyes unfurl to the world sometime during the second week.

By three weeks old, a kitten boasts a finely tuned sense of smell and can now see well enough to locate their nurturing mother. This window, spanning from the second to the seventh week, marks a crucial phase of socialization. Gentle handling by their owner and exposure to a spectrum of experiences are paramount during this period, shaping the kitten’s disposition towards humans and the world at large, averting the development of fearful or aggressive tendencies.

Ideally, the kitten’s owner and household members should tenderly interact with them for 15 to 40 minutes daily throughout their initial seven weeks. Such interaction not only stimulates their cognitive growth but also fosters a more adept and inquisitive learner, culminating in a more playful and inquiring companion.

Around the one-month mark, a kitten’s baby teeth make their debut. By five weeks, they exhibit a repertoire of skills, including running, pouncing, and the ability to correct themselves after a stumble. Grooming becomes part of their routine, both self-care and in interaction with their littermates.

Between six to eight weeks, kittens transition to solid food, though their mother may continue to allow them to suckle for a time. She also starts extending her absences, preparing them for greater independence.

Play among kittens holds multifaceted significance. It fortifies their physical prowess, rendering them more robust and agile. Moreover, it imparts essential social aptitudes, equipping them to navigate interactions with fellow felines and humans.

Crucially, kittens glean a wealth of vital skills from their mother, typically culminating by the twelve-week mark. This underscores the recommendation by breeders and authorities to refrain from adopting out kittens before this pivotal juncture, as premature separation may result in behavioral issues stemming from missed lessons.

At six months, a cat’s adult teeth fully emerge, coinciding with their attainment of sexual maturity. Some veterinarians opt to extract any remaining baby teeth concurrent with spaying or neutering. By this age, a kitten should have received all necessary vaccinations, ensuring a healthy and well-prepared transition into adulthood.

What Is a Teacup Cat?

Teacup cats are intentionally bred for their diminutive size, typically weighing about two-thirds less than the standard members of their breed. Some may weigh as little as five pounds, and the majority of teacup cats trace their lineage back to Persians.

The breeding process for teacup cats may appear straightforward: a breeder pairs a small male with a petite female, resulting in a litter of diminutive kittens. However, this selective breeding for size often leads to a host of health issues. One notable concern is their reduced ability to regulate body temperature, rendering them more susceptible to extreme temperatures.

Additionally, teacup cats are more prone to skeletal and joint problems, including the development of arthritis. They also face an elevated risk of dental issues.

Normal-sized Persians already contend with health challenges due to their extremely flat faces, and these issues are further exacerbated in teacup Persians. For instance, conventional Persians often grapple with breathing difficulties due to their small, stubby noses. In the case of teacup Persians, with even tinier nasal passages, respiratory problems like asthma are even more likely.

Polycystic kidney disease is a common affliction among Persians. Teacup Persians, with their smaller kidneys, may face an amplified susceptibility to this condition compared to their full-sized counterparts. Moreover, teacup Persians encounter increased difficulty in chewing food and are more prone to infections of the nose and eyes.

It’s important to consider these potential health challenges before choosing a teacup cat as a pet, as their small size can come with significant well-being concerns.

How Long Does a Cat’s Gestation Last?

A cat’s gestation period, or pregnancy, spans a variable range of 58 to 72 days, with the majority falling within 63 to 66 days.

In their first pregnancy, a cat will typically give birth to two or three kittens. However, once a cat reaches the age of three or more, their litters tend to grow in size, often consisting of four or five kittens. As a cat continues to age, the size of their litters may gradually diminish.

Certain breeds, such as the Siamese, Burmese, and Oriental Shorthair, tend to have extended gestation periods and larger litters compared to other breeds. Notably, the Guinness Book of World Records documents an extraordinary case of a Siamese/Burmese mix that set a record for the largest cat litter. Astonishingly, she bore 19 kittens, though tragically, four of them were stillborn. This remarkable event serves as a testament to the astounding variability in feline reproductive patterns.


When do most cats reach puberty?

Most cats reach puberty at around 6 or 7 months of age. However, this can vary depending on the breed, with some reaching it as early as 4 months or as late as 10 months.

How is a kitten typically defined?

For most people, including cat food manufacturers, a kitten is considered a juvenile cat under a year old. Veterinarians, on the other hand, often define a kitten as a young cat that hasn’t reached puberty yet.

What are the different life stages of a cat according to veterinarians?

Veterinarians categorize cats into different life stages. Kittens are cats that haven’t reached puberty, usually around six months old. Junior cats are akin to teenagers, still growing and full of energy. Prime and mature cats are young and middle-aged adults, respectively. Senior and geriatric categories refer to older cats.

What is the average lifespan of a cat?

Cats generally have a life expectancy of around 15 years. However, this can vary significantly depending on the breed. Some breeds, like the American Shorthair, can live up to 20 years.

Can a cat’s breed affect its lifespan?

Yes, a cat’s breed can significantly influence its lifespan. While the average is around 15 years, certain breeds, like the American Shorthair, are known to live longer, with some reaching up to 20 years.

How fast do kittens grow?

Kittens grow rapidly, especially in their first year. They experience significant physical and behavioral changes during this period, transitioning from playful juveniles to more independent, young adults.

What are signs that a cat is entering puberty?

Signs of a cat entering puberty include changes in behavior, increased territorial marking, and, in female cats, the onset of their heat cycle. These signs usually manifest around 6 to 7 months of age.

How can I ensure my kitten grows up healthy?

To ensure your kitten grows up healthy, provide a balanced diet, regular exercise, and routine veterinary check-ups. Proper socialization and mental stimulation are also crucial for their overall well-being.


The journey of a kitten growing into adulthood is a fascinating and complex one, influenced by various factors, including breed and individual development. While most cats reach puberty between 6 and 7 months of age, the definition of a kitten can vary between cat owners and veterinarians. Understanding the distinct life stages of cats, from kittens to seniors, helps us appreciate the unique needs and behaviors associated with each phase.

It’s essential to recognize that a cat’s lifespan is not one-size-fits-all; it depends significantly on the breed. While the average lifespan is around 15 years, some breeds, like the American Shorthair, enjoy longer lives, extending up to 20 years.

As we watch our kittens grow, it’s crucial to provide them with the care and attention they need at each stage of their development. Ensuring a balanced diet, regular exercise, socialization, and routine veterinary care contributes to their overall health and happiness.

Michael R

Michael R

I'm a publisher and editor at Cat Guide 101. I imagine that since you’re here, you likely own a cat — or two! — so helping you better understand them is my aim. I'd like to invite you to check out our about page to learn more about the Cat Guide 101 story.

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