Finding a kitten can be exciting, but it often comes with an important question: How old is this kitten? Whether you rescued a stray kitten, adopted one without knowing its birth date, or are caring for a litter, estimating a kitten’s age helps you provide the right food, care, and medical attention.
The good news is that kittens go through predictable stages of development. By looking at their eyes, ears, teeth, weight, movement, and behavior, you can get a fairly accurate idea of their age.
In this guide, we’re going to teach you how to figure out how old your kitten is, what clues to look out for, and when it’s the right time to visit a vet for an expert opinion.
Why Knowing a Kitten’s Age Matters
A kitten’s age affects nearly every aspect of their care.
Knowing roughly how old they are helps you:
- Choose the right food for them
- Work out how often to feed them
- Plan their vaccinations
- Keep track of their growth and development
- Understand when to expect changes in their behaviour
- Schedule when to get them spayed or neutered
Young kittens have completely different needs to older kittens, so estimating age is an important first step.
How to Tell How Old a Kitten Is: Key Signs to Look For
There are a few key physical and behavioural signs that can help you estimate a kitten’s age.
Eyes
A kitten’s eyes give you a good idea of how old they are.
0-1 week old
- Eyes are completely shut and can’t focus
- Usually asleep and nursing all the time
1-2 weeks old
- Eyes start to open a bit
- Normally they’re blue
- Still developing their vision
3-6 weeks old
- Eyes are fully open
- Better coordination
- More alert and curious
7 weeks and older
- Eye colour might start changing from blue
- Adult eye colour is starting to develop
It’s worth noting that eye color alone won’t tell you the exact age, but it can be a useful hint.
Ears
A kitten’s ears change pretty quickly in the first few weeks.
Newborn
- Ears are folded back against the head
1-2 weeks old
- Ears start to unfold and stand up gradually
3 weeks old and up
- Ears are fully upright and can hear sounds
If their ears are still folded, the kitten is likely less than 2 weeks old.
Using Teeth to Guess a Kitten’s Age
Teeth are one of the best ways to estimate age.
2-3 weeks old
The first baby teeth usually come in.
These include:
- Tiny front teeth (incisors)
3-4 weeks old
More baby teeth start appearing.
4-6 weeks old
Canine teeth become visible.
6-8 weeks old
Most baby teeth are showing.
3-4 months old
Permanent adult teeth start replacing baby teeth.
6 months old
Most kittens have a full set of adult teeth.
If you can safely check the kitten’s mouth, teeth can give you a pretty good idea of their age.
Weight as an Age Indicator
A healthy kitten generally gains weight at a pretty predictable rate.
A rough guide is:
- Newborn: 3-5 ounces
- 1 week old: 5-7 ounces
- 2 weeks old: 7-10 ounces
- 3 weeks old: 10-14 ounces
- 4 weeks old: around 1 pound
- 8 weeks old: around 2 pounds
Lots of vets use the simple rule:
A kitten usually gains about one pound per month during their early growth.
Weight alone is not perfect because nutrition and health can affect growth, but it is a good clue.
How a Kitten’s Behaviour Changes with Age
Behaviour can also tell you a lot about a kitten’s age.
0-2 weeks old
- Spends most of their time sleeping
- Can’t walk properly
- Completely dependent on their mum or you
2-3 weeks old
- Starts wobbling around
- Becoming more aware of their surroundings
3-4 weeks old
- Walking improves
- Starts exploring
- Playing with siblings begins
5-7 weeks old
- Very active
- Running and climbing
- Learning social skills
8 weeks old and up
- Independent
- Full of energy
- Eating solid food regularly
Watching how a kitten moves and interacts can give you some useful age clues.
Kitten Age Chart
0-1 week old
- Eyes are shut
- Ears are folded
- Can’t walk
- Needs constant care
2 weeks old
- Eyes are starting to open
- Ears are beginning to stand up
- Limited movement
3 weeks old
- Walking slowly
- Baby teeth are starting to come in
- More alert
4 weeks old
- Playtime begins
- Better balance
- Weaning may start
5-6 weeks old
- Running and exploring
- Most baby teeth are visible
7-8 weeks old
- Fully mobile
- Eating kitten food
- Super playful 3 to 6 Months
Kittens in this life stage experience rapid growth and change.
- You can see adult teeth starting to pop out
- They’re getting a lot more independent as they develop
- Their whole world is opening up, and they’re learning to take on more responsibilities.
What to Do If You Find a Stray Kitten?
If you find a stray kitten, knowing how to tell the age of a kitten becomes an essential skill.
Check Those Physical Signs
Look at some key areas to get an idea of how old they might be:
- Their eyes are a good start – do they seem alert and open or still closed?
- Their ears are another clue – are they up and perked or still folded?
- Take a peek at their teeth – are they baby teeth or adult teeth starting to come in?
- How does their weight compare to other kittens of the same age?
- Is the kitten running around like crazy or still pretty sluggish?
Getting That Kitten Warm
Young kittens struggle to stay warm – it’s not something they can regulate on their own.
So here’s what you can do to help:\
- Blankets can be a lifesaver – get some warm ones to snuggle into\
- A heating pad on a low setting can also help (just use caution and make sure it’s safe)\
- Give them a quiet, safe space to curl up in
Time to Get the Vet Involved
A vet is the best person to get an accurate age assessment, check the kitten’s overall health, spot any parasites and get advice on feeding schedules and vaccinations.
When Should Kittens Stop Just Munching on Mother’s Milk?
Lots of new cat owners are curious about this.
Birth to 4 Weeks
For the first month or so, kittens mainly just rely on that milk or a special kitten formula if they’re not nursing from their mother.
Getting Close to 4 Weeks
Weaning usually starts to kick in – you might start introducing some kitten food to their diet.
6 to 8 Weeks
By this age, most kittens can start eating kitten food on a regular basis – either wet or dry.
Knowing your kitten’s age helps you get their nutrition right from the start.
Common Mistakes When Estimating a Kitten’s Age
Don’t Go Just On Size
Some kittens are naturally a bit smaller or larger than average – so just looking at their size isn’t a good enough indicator of age.
Overlooking Dental Development
Teeth are a great way to estimate age – it’s way more accurate than just looking at their physical size.
Assuming Every Kitten Grows at the Same Rate
But every kitten is different. Nutrition, genetics and health all play a part in how fast they grow.
Skipping a Vet Checkup
Rescued kittens are especially in need of a checkup to make sure everything is okay – and a vet is the best person to get advice from.
Frequently Asked Questions
How Do I Know If a Kitten is Under a Week Old?
Kittens younger than a week have their eyes closed, ears folded in and are pretty inactive.
When Do Kittens Start Opening Their Eyes?
Most kittens start opening their peepers between 7 and 14 days after they’re born.
How Old Is a Kitten That Weighs 2 Pounds?
For a healthy kitten weighing 2 pounds, it’s likely to be around 8 weeks old.
Can a Vet Tell Me Exactly How Old a Kitten Is?
A vet can usually give you a pretty close estimate based on the kitten’s physical development and dental growth.
Conclusion
Learning how to tell the age of a kitten can make a huge difference in giving them the right care as they grow and develop. Take a look at those eyes, ears, teeth, weight and behaviour – and you can make a pretty good estimate of their age.
Of course those signs aren’t 100% accurate – but a vet is the best person to get the real lowdown on your kitten’s age and make sure they get all the care they need to grow and stay healthy. Knowing your kitten’s age from the start is one of the best things you can do to give them the best start in life.