Kitten Age Calculator
How Old Is My Kitten?
Check your kitten's eyes, ears, teeth, weight, and movement to estimate its age in weeks.
Select at least one sign above to estimate your kitten's age.
This is an estimate for general reference only — for exact age and health checks, consult a veterinarian.
Why knowing kitten age matters
Knowing how old is a kitten matters more than most new owners realize. A kitten's age decides everything: how often to feed it, when to start weaning, when to give vaccines, and when it is old enough to be adopted or neutered. A kitten that is only 3 weeks old still needs milk and a heat source, while a 6-week-old is nearly ready for solid food. If you misjudge how old is a kitten by even a week, you could feed it the wrong food or miss a vaccine window.
How to tell how old a kitten is
Wondering how old is a kitten in your home? Look at these five signals in order of reliability — teeth are the single most accurate indicator, followed by weight.
- Eyes: closed at birth, start opening 8–12 days, fully open (blue) by 2 weeks, adult color from about 7 weeks.
- Ears: folded flat at birth, start unfolding around 7 days, fully upright by 3 weeks.
- Teeth: incisors at 3 weeks, canines at 4 weeks, premolars at 5 weeks, full baby teeth by 6 weeks — the most reliable signal.
- Movement: wobbly standing at 2 weeks, steady walking at 3 weeks, running and playing by 4 weeks, jumping and hunting play by 6 weeks.
- Weight: roughly +100g per week starting from a 75–150g birth weight.
Kitten Age Chart
Full week-by-week development chart from birth to 8 weeks.
| Week | Eyes | Ears | Teeth | Weight (g) | Activity |
|---|---|---|---|---|---|
| Birth (0 wk) | Closed | Folded, flat to head | None | 75–150 | Can only crawl |
| 1 week | Closed (opens 8–12 days) | Starting to unfold | None | 150–250 | Can only crawl |
| 2 weeks | Fully open, blue | Half-up, small and round | None | 250–350 | Wobbly standing |
| 3 weeks | Fully open, blue | Fully upright | Front incisors erupting | 350–450 | Steady walking |
| 4 weeks | Fully open, blue | Upright | Canines erupting | 350–450 | Running & playing |
| 5 weeks | Fully open | Upright | Premolars erupting | 550–650 | Running, jumping |
| 6 weeks | Fully open | Upright | Full set of baby teeth | 650–750 | Jumping, pouncing/hunting play |
| 7 weeks | Starting adult color | Upright | Full set of baby teeth | 750–850 | Highly active |
| 8 weeks | Adult color | Upright | Full set of baby teeth | 850–950 | Fully independent |
Kitten weight by age
Weight is one of the most reliable single indicators of kitten age, but it can vary with breed, litter size, and nutrition — combine it with the teeth signal for a more accurate estimate. As a rule of thumb, kittens gain about 100 grams (roughly 3.5 oz) per week. Tracking that weekly gain is one of the simplest ways to answer how old is a kitten when you don't have a birth date to go on.
Kitten care by age
- 0–1 week: eyes and ears closed; needs feeding every 2 hours, gentle stimulation to eliminate, and a warm 85–90°F environment.
- 2 weeks: eyes open and the first deworming can begin.
- 3 weeks: introduce a litter box and start offering soft food.
- 5 weeks: weaning begins in earnest with wet food.
- 6 weeks: first FVRCP vaccine; this is also when figuring out how old is a kitten by teeth becomes easiest, because the full set of baby teeth is now in.
- 8 weeks: at about 2 pounds, the kitten can be spayed/neutered and adopted.
FAQ
- When do kittens open their eyes?
- Kittens' eyes usually start opening between 8 and 12 days old, and are fully open by around 2 weeks.
- When do kittens start eating solid food?
- Weaning typically begins around 5 weeks old, when kittens start eating wet food alongside nursing.
- When can a kitten be adopted?
- Most shelters wait until a kitten is about 8 weeks old and around 2 pounds, which is also the typical minimum age for spay/neuter.
- How much should a kitten weigh?
- Kittens are born around 75–150 grams and gain roughly 100 grams per week, reaching about 850–950 grams by 8 weeks.
- Is my kitten 2 weeks or 4 weeks old?
- Check the teeth: a 2-week-old kitten has no teeth yet, while a 4-week-old kitten already has canine teeth coming in.
- How old is a kitten when it opens its eyes?
- A kitten opens its eyes between 8 and 12 days old, and they are fully open by 2 weeks.