Care & Healthy Living

Kitten Development: Understanding a Kitten's Major Growth Milestones

By

Hannah Shaw

Updated Jul. 18, 2025

Adobe Stock/Happy monkey

In This Article

The first eight weeks of a kitten’s life are a whirlwind of developmental changes. As newborns, kittens are defenseless, blind, and fit in the palm of your hand. But by 8 weeks of age, they’re running, playing, and looking like miniature cats.

Each week, the kitten will have different needs in terms of feeding, bathroom help, medical support, and warmth. It’s important to know how to identify a kitten’s age, as this determines what care the kitten needs and whether the kitten is developing normally.

Here’s what you need to know about the developmental milestones of a kitten’s first eight weeks of life. 

Kitten Age Chart

Kitten Age

Newborn Kittens

Average weight: 1.8–5.3 ounces (50–150 grams)

Newborn kittens will have their eyes closed and their ears folded. They will have no teeth and their gums, nose, and paws may appear bright pink in color. They do not yet have a gag reflex or the ability to thermoregulate.

The umbilical cord will be attached and will fall off on its own around 4 to 5 days of age. Their claws will be non-retractable.

At this age, they cannot hear or see; they can only navigate the world around them through scent and through seeking warmth and comfort.

Newborns will sleep for the majority of the day. Newborn kittens cannot defend themselves or walk, but they may be able to move around by crawling. A healthy newborn will wiggle and meow if handled.

A kitten’s temperature should be 95–97 degrees Fahrenheit at birth. It is critical to provide a gentle heat source, like a heating pad, to keep the kitten warm and stable. The kitten's environment should be kept between 85–90 degrees at this time.

Care

Newborn kittens belong with their mother full-time. The mother will provide them with food, cleaning, warmth, and bathroom support.

If no mother is present, kittens must be bottle fed with kitten milk replacer every two hours by a knowledgeable caregiver, stimulated to go to the bathroom, and kept at an appropriate temperature.

1-Week-Old Kittens

Average weight: 5.3–8.8 ounces (150–250 grams). By 1 week of age, the kitten should have roughly doubled their birth weight.

One-week-old kittens will still have their eyes closed, but no umbilical cord. They will still have no teeth, and their claws will still be non-retractable. At around 7 days old, the ear canals will slowly begin to open and the ears will slightly unfold.

At 8–12 days old, the eyes will slowly begin to open, which can occur over the course of several days. One eye may open more quickly than the other; it’s important to let the kitten’s eyes open at their own pace. All kittens will be born with blue eyes, which will transition to an adult eye color with age.

One-week-old kittens, though larger than newborns, will still be mostly uncoordinated and will similarly sleep for the majority of the day. At this age, they should be able to hold their head up, move by wiggling their limbs, and be active and vocal if handled.

At this age, kittens should be 97–98 degrees F. It is critical to provide a gentle heat source to keep the kitten warm and stable. The kitten's environment should be kept around 85 degrees at this time.

One-week-old kittens belong with their mother full-time. If no mother is present, they must be fed with a bottle and kitten formula every two to three hours by a knowledgeable caregiver, stimulated to go to the bathroom, and kept an appropriate temperature.

2-Week-Old Kittens

Average weight: 8.8–12.3 ounces (250–350 grams)

At 2 weeks of age, kittens' eyes will be fully open and baby blue. Their vision will be poor, and they will not be able to see at long distances. The ear canals will be open, and the ears will be small and rounded, like a bear cub.

If you open the kitten’s mouth, you will find that there are still no teeth. Their claws will still be non-retractable.

Two-week-old kittens are becoming more coordinated and will be beginning to attempt their first steps. But they will be wobbly on their feet and uncoordinated.

Kittens at this age may exhibit some curiosity about the world around them, will not yet be playing, and will spend the majority of their time sleeping.

Kittens should be 98–99 degrees F. It is critical to provide a gentle heat source to keep the kitten warm and stable. The kitten's environment should be kept around 80 degrees at this time.

Two-week-old kittens belong with their mother full-time. If no mother is present, they must be fed with a bottle and kitten formula every three to four hours by a knowledgeable caregiver, stimulated to go to the bathroom, and kept an appropriate temperature. Two-week-old kittens may begin a dewormer.

3-Week-Old Kittens

Average weight: 12.3–15.9 ounces (350–450 grams)

At 3 weeks of age, kittens will have blue eyes and small ears that are beginning to point upward, like a miniature cat. The kitten’s vision and hearing will be slowly improving.

At this age, a kitten's first baby teeth will begin to emerge. The tiny teeth at the front of the mouth, called the incisors, will start to come through the gums. Kittens will slowly begin retracting their claws.

At this age, kittens will be walking and exploring their surroundings, including the litter box. They may begin to become curious about cat toys, though they are not yet able to run or chase after moving objects.

They will sleep frequently and may begin some small self-grooming behaviors. During this week, their coordination will be improving rapidly.

Three-week-old kittens will be 99–100 degrees F. They still require a heat source but will be more active and may stray from it when not sleeping. The kitten's environment should be around 75 degrees at this time.

Three-week-old kittens belong with their mother full-time. If no mother is present, they must be fed with a bottle and kitten formula every four to five hours by a knowledgeable caregiver.

Though they may not use it yet, introduce a shallow cat litter box with a non-clumping cat litter, like Fresh Step Premium Scented Non-Clumping Cat Litter.

Monitor them to make sure they don’t try to eat the litter.

4-Week-Old Kittens

Average weight: 15.9 ounces–1.2 pounds (450–550 grams)

At 4 weeks of age, kittens will have much improved vision and hearing. The kitten's teeth will continue to develop; the long teeth next to the incisors, called the canine teeth, will start to come through the gums. Their claws will be retractable.

Four-week-old kittens will be confidently exploring and developing more coordination that allows them to walk, run, and even begin to play. With their improved senses, they will be notably more responsive, making frequent eye contact with caregivers and reacting to sights and sounds in the environment.

Their grooming skills may still be limited but improving.

This age marks a transition from needing to be stimulated by their mothers to go to the bathroom to being able to eliminate on their own. Where previously they may have only explored the litter box, now they’ll begin using it.

Four-week-old kittens will be 99–101 degrees F. Continue providing a heat source, although they will likely use it only when resting. The kitten's environment should stay comfortably warm and never colder than 70–75 degrees.

Four-week-old kittens belong with their mother full-time. Orphans of this age should be bottle fed every five hours, including overnight.

Four-week-old kittens will generally be using the litter box. Most kittens will instinctually seek out the litter box to do their business, but some may need litter training.

Stick to non-clumping litter at this age. Once kittens are a little older, about 8-10 weeks of age, you can switch to a clumping litter, like Fresh Step Heavy Duty 30 Day Odor Control with Febreze Freshness Clumping Cat Litter.

At this age kittens typically progress from being curious about toys to beginning to play with toys. Now is a good time to start engaging them in playtime.

5-Week-Old Kittens

Average weight: 1.2–1.4 pounds (550–650 grams)

At 5 weeks of age, a kitten's baby teeth will continue to develop and the premolars will start to emerge. Their eyes will be blue, ears will be growing and pointed, and claws will be retractable.

Five-week-old kittens will be running and playing confidently. They will be developing social skills with humans and other animals. Their grooming skills will be improving. They will have perfected their use of the litter box by this age.

Kittens will be 100-101 degrees F at this age. A heating source is no longer required as long as the environment is a comfortable temperature of 70–75 degrees.

Five-week-old kittens, if healthy, may begin the weaning process. Kittens should receive ample “slurry” or wet kitten food, in addition to access to their mother’s milk or, if orphaned, a bottle.

If weaned, food and water should be provided at all times. Always provide supplemental feeding and ensure that the kitten is maintaining a healthy weight and body condition during weaning. Provide a shallow litter box at all times.

6-Week-Old Kittens

Average weight: 1.4–1.7 pounds (650–750 grams)

At 6 weeks of age, a kitten's baby teeth will begin to reach their final stage of early development. The molars will start to emerge. The eyes will still be blue, and vision and hearing will be fully developed.

Six-week-old kittens will be socializing confidently with peers, play-fighting, pouncing, and defending themselves. They will be curious about their surroundings and eager to explore. They will be perfecting their grooming skills. Six-week-old kittens are becoming coordinated enough to jump off short furniture and land on their feet.

Six-week-old kittens will be 100–101 degrees F. At this age, a heating source is no longer required as long as the environment is a comfortable temperature of 70–75 degrees.

Kittens at this age should be receiving ample kitten wet food, though they might not be completely weaned yet. Provide access to water, food, and a shallow litter box at all times. At six weeks, kittens can receive their first FVRCP vaccine to protect them against viruses (rhinotracheitis, calicivirus, and panleukopenia).

7-Week-Old Kittens

Average weight: 1.7–1.9 pounds (750–850 grams)

All baby teeth will be present at 7 weeks of age. The kitten’s eye color will be changing, and the adult eye color will begin to emerge. Male kittens’ testicles may begin to descend around 7 weeks.

Seven-week-old kittens will experience a spike in energy. Sleep will decrease and time spent playing will increase. At this age, kittens are able to run, climb cat trees, and confidently jump off of furniture.

Average Temperature

Seven-week-old kittens will be 100–101 degrees F. At this age, a heating source is no longer required as long as the environment is a comfortable temperature of 70–75 degrees.

Kittens should receive ample kitten wet food, and may have dry kitten food as a supplement. Provide access to water, food, and a shallow litter box at all times.

8-Week-Old Kittens

Average weight: 1.9–2.1 pounds (850–950 grams)

All baby teeth will be present at 8 weeks of age. The eyes will be completely transitioned to their adult color of green, yellow, brown, or blue. The ears will be proportionate.

Eight-week-old kittens will be energetic and independent. Their agility and coordination will be nearly fully developed.

Kittens at this age will be 100–101 degrees F. A heating source is no longer required as long as the environment is a comfortable temperature of 70–75 degrees.

Kittens should receive access to canned and dry kitten food three to four times per day, and they can receive the bulk of their calories from dry food if they choose. Provide access to water and a shallow litter box at all times.

If two weeks have passed since their first FVRCP vaccine, kittens may receive a booster at this time. If the kitten has not been dewormed, oral dewormer can be administered. It is also a good idea to have a fecal test run to check for internal parasites.

At this age, if they are 2 pounds and healthy, they may be spayed or neutered, microchipped, and adopted. 

When Is a Cat Fully Grown?

Cats are typically considered fully grown at about 9 months of age, when their adult canine teeth (the fang teeth) have grown in and they have reached their mature size, which averages 8–10 pounds. 

At this stage, they will still have a lot of energy and kitten behaviors, such as climbing furniture and chasing feet, but physically they’re well on their way to maturity.

WRITTEN BY

Hannah Shaw

Freelance Writer

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