Found a tiny kitten? Not sure if it’s a newborn or a few weeks old?
How to Tell Kitten Age? Here’s a simple way to estimate your kitten’s age fast using visible signs like teeth, eyes, weight, and behavior.
Knowing a kitten’s age helps you decide what to feed it, when to vaccinate, and how to take care of it safely. Whether you’re a new pet parent or rescued a stray, this guide makes it easy to figure out how old your kitten is, even without a vet visit.
How Vets Estimate a Kitten’s Age?
Veterinarians use a mix of physical and behavioral cues to determine how old a kitten is. According to veterinary clinics like Madison Park Vet, the following indicators give the best estimates:
Teeth development: The most reliable sign — baby teeth erupt by 2–4 weeks, adult teeth by 3–6 months.
Weight & size: Healthy kittens gain around 100 g per week.
Eyes & ears: Eyes open around week 2; ears stand upright around week 3.
Behavior & mobility: Walking, playing, and grooming appear gradually by weeks 4–8.
Each of these factors is covered in detail below.
How to Tell Kitten Age by Teeth
Baby vs Adult Teeth: Timeline
| Age | Teeth Development | Notes |
|---|---|---|
| 0–2 weeks | No visible teeth | Nursing only |
| 2–3 weeks | Tiny incisors appear | Front teeth erupt first |
| 3–4 weeks | Canines visible | Kitten starts nibbling |
| 5–6 weeks | Premolars appear | Full baby set forms |
| 3–4 months | Adult incisors replace baby ones | Mixed dentition stage |
| 5–6 months | All adult teeth are in place | Permanent set complete |
How to Safely Check Your Kitten’s Teeth?
Could you wash your hands and find gentle lighting?
Hold the kitten in a towel to keep it calm.
Gently lift the lips don’t pull the jaw open.
Note which teeth are visible and their size.
Compare with the table above.
How to Tell Kitten Age by Weight & Size
Kitten Weight Chart
| Age (weeks) | Average Weight (grams) | Common Traits |
|---|---|---|
| 1 week | 85–115 g | Eyes closed, sleeps constantly |
| 2 weeks | 170–225 g | Eyes start opening |
| 3 weeks | 225–300 g | Begins crawling |
| 4 weeks | 350–450 g | Teeth emerging |
| 6 weeks | 600–700 g | Eats soft food |
| 8 weeks | 800–950 g | Playful, social |
| 12 weeks | 1.0–1.2 kg | Fully mobile, weaned |
How to Weigh a Kitten Safely?
Use a digital kitchen scale with a small bowl.
Place a soft towel for comfort.
Weigh at the same time each day for accuracy.
Record changes — steady gain means good health.
Eyes, Ears & Other Physical Signs
Eye Development & Color Change
| Age | Eye Appearance | Meaning |
|---|---|---|
| 0–7 days | Closed tightly | Newborn |
| 7–14 days | Opening, cloudy blue | 2-week range |
| 3–4 weeks | Fully open, bright blue | Early curiosity |
| 6–8 weeks | Color begins shifting | Transitional |
| 3 months + | Green, gold, or amber | Mature eyes |
Ear & Fur Changes
0–1 week: ears folded.
2–3 weeks: ears start to lift.
4 weeks: ears fully upright.
Fur: short and fuzzy early on; sleekens by 2 months.
Behavior & Motor Milestones (Week-by-Week)
| Age | Behavior | Care Tips |
|---|---|---|
| 0–2 weeks | Sleeps 90% of the time | Keep warm, bottle-feed |
| 3–4 weeks | Crawls, starts grooming | Litter training begins |
| 5–6 weeks | Runs, explores | Introduce solid food |
| 7–8 weeks | Very playful | Start socializing |
| 3–6 months | Jumps, hunts toys | Vaccination phase |
Caregiver Checklist
Feed on schedule (milk → wet → dry food).
Encourage gentle play for coordination.
Keep the environment warm and safe.
Schedule the first vet visit by 6–8 weeks.
When to See a Vet & What They Check
Vaccination: first shots at 6–8 weeks, boosters every 3–4 weeks.
Deworming: starts at 2 weeks, repeats every 2 weeks until 3 months.
Exam checklist: teeth stage, weight, eyes/ears, reflexes, hydration.
If your kitten isn’t gaining weight or has discharge around the eyes or nose see a vet immediately.
Special Cases: Feral, Orphaned & Breed Variations
(Cluster C7)
Feral kittens may develop more slowly due to malnutrition.
Orphaned kittens: need extra warmth & bottle-feeding every 2–3 hours.
Breed differences: larger breeds (e.g., Maine Coon) grow more slowly; short-haired cats mature faster.
Local shelters and rescues can assist. Contact your nearest animal welfare center if unsure.
Convert Kitten Age to Human Years + Tools
Wondering how old your kitten would be if it were human?
Use our interactive Cat Age Calculator to instantly convert your kitten’s months into human years.
For example:
A 6-month-old kitten ≈ 10-year-old human
A 1-year-old cat ≈ 15-year-old human
Quick Reference: Kitten Age Chart (Printable)
| Age | Weight | Teeth | Eyes & Ears | Behavior |
|---|---|---|---|---|
| 0–1 wk | 85–115 g | None | Eyes closed | Sleeps constantly |
| 2–3 wk | 170–225 g | Incisors | Eyes opening | Crawling |
| 4–5 wk | 300–450 g | Premolars | Ears upright | Walking |
| 6–8 wk | 600–900 g | Full baby set | Color shift | Playful |
| 3–6 mo | 1–2 kg | Adult teeth | Mature look | Active |
Data and veterinary insights adapted from the ASPCA, Cats Protection UK, Madison Park Veterinary Hospital, and the American Veterinary Medical Association (AVMA).
FAQ
Can a vet tell a kitten’s exact age?
Not to the day, but by examining teeth, eyes, and weight, vets can estimate within 1–2 weeks.
How to tell a kitten’s age if it has no teeth?
Look for closed eyes and folded ears, likely under 2 weeks old.
How much should a 2-month-old kitten weigh?
About 800–950 grams, depending on breed.
When do kittens start eating solid food?
Around 4 weeks of age.
At what age can kittens leave their mother?
After 8 weeks, they’re weaned and socialized.
When do kittens get their adult teeth?
Between 3–6 months.
Can I estimate kitten age by eye color?
Yes, blue eyes mean under 2 months; color change shows growth.
How fast do kittens grow?
Rapidly doubling weight within weeks.