MyyCat · Free kitten care tool
Kitten Age Estimator: How Old Is My Kitten?
Found a kitten or adopted one with no birth date? Enter its weight and what you can see, such as eyes, ears, teeth and how it moves, and get an estimated age range with an approximate birth date and the care that fits that age.
- Weight plus 6 milestones
- Age range, not a guess
- Shows conflicting clues
- Print or copy results
Step 1 · Observe
Tell us what you can see
Answer as many questions as you can. Choose “Not sure” for anything you cannot check. The more clues you give, the narrower the estimate.
Step 2 · Result
Estimated age
How each clue fits
Each bar shows the age range a clue usually points to. The shaded band is the estimate where your clues overlap.
Care at this age
This is an educational estimate from typical development ranges. Kittens develop at different rates, and illness or poor nutrition can make a kitten look younger than it is. A veterinarian can give a more reliable estimate.
Kitten age chart: what changes week by week
These are typical ranges reported by animal welfare organizations and veterinary references. Individual kittens vary, so use several clues together.
| Clue | Typical age |
|---|---|
| Umbilical cord stump still attached | First few days of life |
| Eyes closed, ears folded | Under about 1 to 2 weeks |
| Eyes starting to open, ears starting to unfold, crawling | About 1 to 2 weeks |
| Eyes and ears fully open, first wobbly steps, baby incisors appearing | About 2 to 4 weeks |
| Weaning onto soft food, using a litter box, playing | About 4 to 6 weeks |
| Baby premolars (back teeth) erupting | About 5 to 6 weeks |
| Full set of 26 baby teeth | About 6 to 8 weeks |
| Adult teeth begin to replace baby teeth | About 4 to 7 months |
Typical kitten weight by week
Healthy kittens are often around 100 g (about 3.5 oz) at birth and usually gain about 7 to 15 g a day, so weight is a useful clue in the first 8 weeks. After that, size varies too much between kittens and breeds for weight alone to estimate age.
| Week of life | Typical weight range |
|---|---|
| Week 1 (days 1–7) | 70–190 g (2.5–6.7 oz) |
| Week 2 (days 8–14) | 149–295 g (5.3–10.4 oz) |
| Week 3 (days 15–21) | 198–400 g (7.0–14.1 oz) |
| Week 4 (days 22–28) | 247–505 g (8.7–17.8 oz) |
| Week 5 (days 29–35) | 296–610 g (10.4–21.5 oz) |
| Week 6 (days 36–42) | 345–715 g (12.2–25.2 oz) |
| Week 7 (days 43–49) | 394–820 g (13.9–28.9 oz) |
| Week 8 (days 50–56) | 443–925 g (15.6–32.6 oz) |
Source: ASPCA Kitten Age and Weight Chart (2023), which notes that weight should be used together with developmental milestones.
How the kitten age estimator works
Each answer you give is matched to the range of ages in days where that sign is usually seen. The estimator then looks for the ages where all your clues overlap. If a weight is entered, it is matched against the ASPCA’s weekly weight ranges for the first 8 weeks (the table above). Because weight varies so much, and underweight kittens can look younger than they are, weight counts as a supporting clue only: it can break a tie, but it never outweighs a developmental sign.
If your clues do not overlap, which is common when a kitten is small for its age or a sign was hard to judge, the tool shows the ages that agree with the most developmental clues and tells you which clues disagree. It always gives a range of at least a week, never an exact age. The estimated birth date is simply today’s date minus the estimated age range.
Ranges used
| Clue | Answer | Ages used |
|---|---|---|
| Cord stump | Still attached | 0 to 7 days |
| Weight | Within an ASPCA weekly range | The weeks whose range includes the weight (supporting clue) |
| Eyes | Closed | 0 to 14 days |
| Starting to open | 7 to 16 days | |
| Fully open, blue | 14 to 49 days | |
| Changing or adult color | 28 days or older | |
| Ears | Folded | 0 to 14 days |
| Unfolding | 7 to 21 days | |
| Upright | 14 days or older | |
| Teeth | None | 0 to 28 days |
| Incisors only | 14 to 35 days | |
| Incisors and baby canines | 21 to 42 days | |
| Full set of baby teeth | 35 to 140 days | |
| Adult teeth coming in | 112 to 210 days | |
| Full adult set | 180 days or older | |
| Movement | Crawls only | 0 to 18 days |
| Wobbly steps | 14 to 28 days | |
| Walks and plays | 21 to 49 days | |
| Runs and pounces | 28 days or older | |
| Eating | Milk only | 0 to 35 days |
| Starting soft food | 21 to 42 days | |
| Eats solid food well | 35 days or older |
Ranges are deliberately generous to allow for normal variation. The baby canine range is approximate: sources agree that canines erupt after the incisors and before the premolars, but give few precise dates.
Sources
- ASPCA. Kitten Age and Weight Chart. 2023.
- Muylle S. Dental Development of Cats. Merck Veterinary Manual, pet owner version. Updated June 2025. Baby incisors erupt at about 2 to 4 weeks and baby premolars at 5 to 6 weeks; most cats have 26 baby teeth and 30 adult teeth, which begin to appear at about 4 to 7 months.
- Alley Cat Allies. How to Determine a Kitten’s Age. Updated October 2025.
Limitations
- The estimate is a range, not an exact age, and it is most precise for kittens under about 8 weeks.
- Underweight, sick or orphaned kittens may look younger than they are.
- Pedigree breeds and very large or small kittens may not follow typical weight ranges.
- Only a veterinarian can examine teeth and overall development reliably.
Frequently asked questions
How can I tell how old a kitten is?
Look at several clues together: weight in the first 8 weeks, whether the eyes and ears are open, which teeth have come in, how well the kitten walks, and whether it is eating solid food. A veterinarian can confirm the estimate during a health check.
When do kittens open their eyes?
Most kittens start to open their eyes at about 1 to 2 weeks of age, and the eyes are usually fully open by about 2 to 3 weeks. All kittens’ eyes are blue at first. Sources differ on timing: the adult color starts to show from about 4 to 7 weeks.
When do kittens get their teeth?
Baby incisors usually appear at about 2 to 4 weeks, followed by the baby canines and then the premolars at about 5 to 6 weeks. Adult teeth start replacing them at about 4 to 7 months.
How much should a kitten weigh at 8 weeks?
The ASPCA chart gives a typical range of about 443 to 925 g (about 1 to 2 lb) at 8 weeks. Steady daily weight gain matters more than a single number, so weigh young kittens regularly.
Can I estimate an adult cat’s age with this tool?
No. Once all adult teeth are in, from about 6 to 7 months, visual clues give only a rough idea. A vet can look at teeth, eyes and overall condition, but even then adult age estimates are approximate.
Related MyyCat guides and tools
Veterinary disclaimer: This estimator gives general educational information. It cannot examine a kitten and does not replace a veterinary health check. Young kittens can become ill very quickly, so contact a vet promptly if a kitten seems unwell. See our veterinary disclaimer.