Determining the age of a kitten can be essential for providing appropriate care, nutrition, and veterinary attention.

Whether you've found an orphaned kitten or adopted one, knowing its age helps ensure it receives the right support during its developmental stages.

While it may not always be an exact science, there are reliable physical and behavioral indicators to estimate a kitten's age.

1. Observing Physical Development

Eyes: Kittens are born with their eyes closed. They begin to open around 7–10 days old, though their vision remains limited. By 2–3 weeks, their eyes are fully open and start transitioning from a cloudy blue color to their permanent shade around 6–7 weeks.

Ears: At birth, kittens have closed, folded ears. By 5–8 days, their ears start to unfold, indicating they are becoming more alert and aware of their surroundings.

Teeth: Examining a kitten's teeth provides one of the most accurate age estimates:

No teeth: 0–2 weeks old

Baby incisors: 2–4 weeks

Baby canines: 3–4 weeks

Baby premolars: 4–6 weeks

2. Size and Weight

Kittens grow rapidly during their first few weeks, and their weight can provide clues about their age.

At birth: Around 85–115 grams

1 week: 150–200 grams

2 weeks: 200–300 grams

4 weeks: 350–450 grams

8 weeks: 800–1,000 grams

A kitchen scale can be a helpful tool to weigh the kitten and estimate its age based on size.

3. Coat and Mobility

Fur Development: Newborn kittens have thin, short fur. By 3–4 weeks, their coat becomes denser, and patterns and colors become more defined. Long-haired breeds will begin to show fluffier coats by 6–8 weeks.

Movement and Coordination: Newborns are wobbly and unable to walk.

By 2–3 weeks, they start crawling and attempting to stand.

Around 4 weeks, kittens gain better coordination and begin exploring their environment.

By 6–8 weeks, they are highly active, running and climbing confidently.

4. Behavioral Clues

A kitten's behavior also evolves as it grows:

0–2 weeks: Kittens sleep most of the time and rely on their mother for warmth and feeding.

3–4 weeks: They begin to play, interact with siblings, and explore their surroundings cautiously.

5–6 weeks: Socialization increases, and they become more curious and independent.

8 weeks and older: Kittens exhibit full playfulness, hunting instincts, and independence, often ready for adoption.

5. Veterinary Assessment

When in doubt, a veterinarian can provide a more accurate estimate of a kitten's age. They may assess the kitten's teeth, weight, and overall physical condition, offering guidance on proper care and feeding schedules.

Judging a kitten's age involves examining physical traits, weight, and behavior. By paying attention to key milestones such as eye and ear development, teething stages, and mobility, you can approximate the kitten's age and cater to its specific needs.

Proper care during these formative weeks ensures the kitten grows into a healthy and happy cat.