Kitten Age Chart: Week-by-Week Growth & Development Guide

Kittens change so quickly that a difference of just one or two weeks can completely change what you see: closed eyes become bright blue eyes, crawling becomes climbing, milk becomes solid food, and a tiny dependent newborn turns into a confident miniature cat.

That is why a kitten age chart is useful—not just for satisfying curiosity, but for understanding what a kitten should roughly be able to do at each stage.

The easiest way to estimate a kitten's age is to look at several clues together: eyes, ears, teeth, walking ability, play behavior, eating, grooming, and overall coordination. Weight can help, but it should never be used alone because normal size varies by breed, nutrition, litter size, and health.

Kitten Age Chart: Week by Week

Use this chart as a practical visual guide. Development does not happen on the exact same day for every kitten, so a range is more useful than a single milestone.

How Accurate Is a Kitten Age Chart?

A kitten age chart is best used as an estimate.

A healthy 4-week-old kitten and an undernourished 5-week-old kitten can look surprisingly similar in size. Long-haired kittens can also look physically bigger than short-haired kittens of the same age.

That is why veterinarians and experienced rescuers look at multiple developmental signs rather than weight alone.

How to Tell a Kitten's Age by Its Eyes

Eyes are one of the easiest early clues.

Newborn kittens are born with their eyes closed. Cats Protection notes that the eyes generally open around 10 days, although the normal range can be broader. Another Cats Protection guide gives a range of approximately 5–14 days.

Young kittens initially have blue-grey eyes. The iris colour begins changing toward the permanent adult colour around four to six weeks, although the final look can take longer to become obvious.

Eye colour is useful as a clue, but it cannot give you an exact birthday.

How to Tell a Kitten's Age by Its Ears

Newborn ears are folded and sit close to the head.

As the kitten moves into the second and third weeks, the ears open and become increasingly upright.

By around three weeks, a kitten's ears usually look much more like the upright ears you expect on an older kitten.

How to Tell a Kitten's Age by Walking

Movement changes dramatically during the first month.

Cats Protection notes that crawling begins around 7–14 days and walking begins at roughly two weeks. Early walking is clumsy and wide-based.

By three weeks, kittens become much more mobile and may start trying to climb out of their nesting box.

VCA notes that by about four weeks, kittens should be able to walk, run and play. At that point, coordination becomes a far more obvious feature of daily behavior.

When Do Kittens Start Eating Solid Food?

Weaning usually begins around three to four weeks of age.

This is a gradual transition, not a one-day switch. Young kittens continue nursing while they learn to lap and eat appropriate kitten food.

By around eight weeks, kittens are typically fully weaned. If a kitten is orphaned, very young or failing to eat properly, feeding needs are more complex and veterinary guidance is important.

When Do Kittens Start Using the Litter Box?

Very young kittens cannot urinate and defecate independently.

VCA and Cats Protection both note that kittens generally begin toileting independently at around three weeks.

Once kittens are mobile, a low, easily accessible litter tray in a quiet area helps them practice the behavior. Most kittens learn quickly because digging and eliminating in loose substrate are natural feline behaviors.

Keep food and water away from the litter area and avoid forcing or frightening the kitten during training.

The 2–7 Week Socialisation Window Matters

A kitten is not only growing physically during this period.

Cats Protection identifies approximately two to seven weeks as the key socialisation period. VCA describes the same period as the most sensitive time for social development.

Positive, gradual exposure can include:

• Gentle handling
• Different people
• Normal household sounds
• Safe toys
• Different floor textures
• Appropriate scratching surfaces
• Positive introduction to a carrier

Socialisation should be gradual. If the kitten appears frightened or distressed, reduce the intensity rather than forcing the experience.

When Can Kittens Leave Their Mother?

Kittens should not be separated from their mother too early.

Cats Protection recommends that kittens raised with their mother stay with her until at least eight weeks old. VCA notes that 8–12 weeks is generally an appropriate age range for kittens to enter a new home because they have had more time to develop social behavior with their mother and littermates.

A kitten looking physically independent at six or seven weeks does not mean it has finished learning from its family group.

When Do Kittens Need Vaccinations?

Vaccination timing varies with region, vaccine type, risk and the individual kitten.

AAHA/AAFP guidance allows the core FPV/FHV-1/FCV series to begin no earlier than six weeks for standard parenteral vaccines and continue every 3–4 weeks until 16–20 weeks of age. FeLV vaccination for kittens can begin as early as eight weeks in the AAHA schedule.

Do not build a vaccine schedule from an internet age chart alone. Your veterinarian should tailor the timing to your kitten, local law, lifestyle and disease risk.

When Do Kittens Get Adult Teeth?

Baby teeth begin appearing in the first few weeks of life.

As kittens grow, those deciduous teeth are replaced by adult teeth. Cats Protection notes that kittens generally have their full set of 30 adult teeth by about six months.

That makes teeth particularly useful for estimating the age of older kittens when eyes and ears no longer provide obvious clues.

When Is a Kitten Fully Grown?

Veterinary life-stage guidance considers cats kittens from birth up to one year.

VCA notes that most cats reach approximately 80–90% of their predicted adult size between 9 and 12 months. Many are mature around that time, while large-breed cats may continue growing until approximately 18 months.

So a one-year-old cat may already look fully grown even though body composition and behavioral maturity can continue changing afterward.

Can You Tell a Kitten's Age by Weight?

Weight is helpful, especially in the first weeks, but it is not precise enough to use alone.

Cats Protection gives a typical newborn range of approximately 90–110 grams and notes that healthy young kittens generally gain weight steadily. But actual weight depends on breed, litter size, nutrition, illness, genetics and whether the kitten was premature or underweight.

A kitten that is much smaller than expected may be younger—or it may simply need medical attention. Developmental signs and veterinary examination are more reliable than guessing from a number on the scale.

What Does a 4-Week-Old Kitten Look Like?

At around four weeks, most kittens are dramatically more mobile than newborns.

They should be able to walk, run and play, their ears are upright, baby teeth are developing, and weaning is underway.

They still need a controlled, safe environment. At this stage, “playful” does not mean ready for unrestricted access to high furniture, stairs, balconies or other household hazards.

What Does an 8-Week-Old Kitten Look Like?

An 8-week-old kitten is usually energetic, coordinated and eating independently.

It can run, pounce, climb, groom, use a litter tray and engage in complex play. This is also around the age when many kittens begin transitioning to a new home after appropriate weaning and socialisation.

Do not confuse independence with adulthood. An 8-week-old kitten is still in an extremely fast period of physical and behavioral development.

How Your Kitten's Home Should Change as They Grow

Whatever the age, introduce new furniture according to the individual kitten's coordination and confidence. Check stability, supervise early use, and make sure a fall from a high platform would not place a very young kitten at risk.

Final Answer: How Old Is My Kitten?

Use several clues together.

Closed eyes and folded ears suggest a newborn. Eyes opening and wobbly walking suggest roughly two weeks. Upright ears, emerging teeth and improving mobility point toward three weeks. Running, playing and beginning to eat solid food suggest roughly four weeks or older. By seven to eight weeks, kittens are highly active, mostly or fully weaned and look like miniature adult cats.

After the first two months, teeth, body development and veterinary records become more useful than eyes and ears for estimating age.

If the kitten's age matters for feeding, vaccines, parasite treatment, illness, neutering or orphan care, let a veterinarian make the final estimate.

Frequently Asked Questions

How can I tell how old a kitten is?

Look at the eyes, ears, teeth, movement, eating behavior and coordination together. These developmental markers are more useful than weight alone.

When do kittens open their eyes?

Eyes generally open during the first two weeks of life, commonly around 10 days, although individual kittens vary.

When do kittens start walking?

Walking starts at roughly two weeks and is initially very wobbly. Coordination improves rapidly during weeks three and four.

When do kittens start eating solid food?

Weaning usually begins around three to four weeks and takes several weeks. Most kittens are fully weaned by about eight weeks.

When do kittens use the litter box?

Kittens generally begin eliminating independently at around three weeks, after which litter training can develop quickly.

When can kittens leave their mother?

Kittens raised with their mother should generally stay with her until at least eight weeks of age.

When do kittens get adult teeth?

Adult teeth replace the baby teeth during kittenhood, with the full set of 30 adult teeth generally present by about six months.

When is a kitten considered an adult cat?

AAHA/AAFP life-stage guidance defines the kitten stage as birth up to one year. Most cats are close to adult size around 9–12 months, although larger breeds can take longer.

Can kitten weight tell you age?

Weight can support an age estimate, especially in very young kittens, but breed, litter size, nutrition and health create too much variation for weight to be used by itself.

What should a 4-week-old kitten be able to do?

Most 4-week-old kittens can walk, run and play, are developing baby teeth, and are beginning the gradual transition toward solid kitten food.

What should an 8-week-old kitten be able to do?

An 8-week-old kitten is usually active, coordinated, eating independently, grooming, playing, climbing and using a litter tray.