🐾 Kitten Age Estimator
Found a kitten, or adopted one with no birthday? Answer what you can see — skip anything you're not sure about — and get an age range, a rough birth date, and what a kitten that age needs next.
How the Estimate Works
Each sign you choose narrows the possible age to a window — closed eyes, for example, mean under about two weeks, and a full set of baby teeth means at least about five. The tool finds the age range that fits all of your answers.
If your answers can't all be true at once, the tool sets aside the least reliable sign first — weight, then eating, then movement — and tells you which one didn't fit. Teeth, eyes and ears are trusted most, because they develop on schedule even in a kitten that has been underfed.
Kitten Development Milestones
| Sign | Typical age |
|---|---|
| Umbilical cord still attached | First few days |
| Eyes open | About 8–14 days |
| Ears stand up | About 3 weeks |
| Baby front teeth (incisors) | About 2.5–3.5 weeks |
| Baby fangs (canines) | About 3–4 weeks |
| Baby back teeth (premolars) | About 5–8 weeks; full baby set by 8 weeks |
| Wobbly walking | About 2–3 weeks |
| Walking steadily, starting to play | About 4 weeks |
| Pouncing and wrestling | About 5 weeks onward |
| Eye colour starts to change from blue | About 4–7 weeks |
| Weaning onto mushy food | About 4–5 weeks |
| Adult front teeth | About 3–3.5 months |
| All adult teeth in | By about 6 months |
Timings vary with breed, nutrition and health, and sources differ by a few days on most of them, which is why the tool works in ranges. Some breeds, such as Siamese, keep blue eyes as adults — if your kitten might be one, leave the eye-colour question as "not sure".
Why Weight Is the Least Reliable Sign
The rough rule is about 1 pound per month up to around 5 months: a 1 lb kitten is about 4 weeks old, 2 lb about 8 weeks, 3 lb about 12 weeks. It works well for a healthy, well-fed kitten. But a kitten that has been living rough, has worms or has been ill will weigh less than its real age, while its teeth and eyes keep developing on time. Large breeds can also run heavier.
That mismatch is useful information in itself. If the tool tells you your kitten's weight doesn't fit its development, weigh it daily on a kitchen scale and mention it to your vet. Our kitten weight chart shows the normal range at every age.
Frequently Asked Questions
How can I tell how old a kitten is?
Look at development first and weight last. Teeth are the most useful single sign: baby front teeth come through at about 2.5–3.5 weeks, the fangs at 3–4 weeks and the back teeth at 5–8 weeks, and adult teeth replace them from about 3 to 6 months. Eyes open at around 8–14 days, ears stand up by about 3 weeks, and kittens walk steadily by about 4 weeks. Weight is a useful cross-check but the least reliable sign on its own.
How old is a kitten whose eyes are still closed?
Usually under about two weeks. Kittens are born with their eyes closed and they open between roughly 8 and 14 days. A kitten this young cannot keep itself warm or go to the toilet on its own, and needs feeding every 2 to 3 hours around the clock, so warmth comes first and a vet visit should happen soon.
How old is a 1-pound kitten?
Usually around 4 weeks. The rough rule is about 1 pound per month up to about 5 months, so a 2-pound kitten is around 8 weeks and a 3-pound kitten around 12 weeks. An underfed or sick kitten weighs less than its true age suggests, and large breeds can be heavier, so check the teeth and eyes too.
Can a vet tell a kitten's exact age?
Not exactly, but closely while the kitten is young. Vets use the same signs this tool asks about, especially the teeth, and in the first two months development changes almost week to week. Once all the adult teeth are in at around 6 months, an estimate becomes much broader.
When does a kitten need its first vaccines?
Kittens typically start their core FVRCP vaccine series at 6–8 weeks old, with boosters every 3–4 weeks until at least 16 weeks. Rabies is usually given at 12–16 weeks. Deworming usually starts earlier, from around 3 weeks of age.
Why doesn't my kitten's weight match its age?
Most often because the kitten has not been eating enough, has intestinal parasites, or has been unwell, all of which hold weight back while teeth and eyes keep developing on schedule. Large breeds such as Maine Coons can run heavier. When weight and development disagree, trust development and ask your vet to check the kitten, because a kitten that is not gaining needs attention quickly.