How Old Is My Kitten? Kitten Age Calculator
Estimate a kitten’s age in weeks from its weight and the milestones you can see. Knowing the age tells you how to feed and care for a found or new kitten.
Tip: a kitchen scale is the best tool. A healthy kitten weighs about 100 g (3.5 oz) at birth and gains roughly 10–15 g (about half an ounce) per day – about 1 pound per month.
Kitten age chart: week by week
| Age | Weight | What you will see |
|---|---|---|
| 0–1 week | 50–150 g (2–5 oz) | Eyes closed, ears folded, umbilical cord still attached |
| 1–2 weeks | 150–250 g (5–9 oz) | Eyes start to open (blue), ears still folded |
| 2–3 weeks | 250–350 g (9–12 oz) | Ears unfold, first wobbly crawling |
| 3–4 weeks | 350–450 g (12–16 oz) | First baby teeth (incisors), starts walking |
| 4–5 weeks | 450–550 g (1–1.2 lb) | Canine teeth, begins eating wet food, uses litter box |
| 5–6 weeks | 550–700 g (1.2–1.5 lb) | Runs and plays, weaning |
| 6–8 weeks | 700–900 g (1.5–2 lb) | Eye color starts to change, all baby teeth in |
| 3 months | about 1.4 kg (3 lb) | Adult teeth start to replace baby teeth |
| 4 months | about 1.8 kg (4 lb) | Adult incisors and canines come in |
| 6 months | about 2.7 kg (6 lb) | All adult teeth, sexual maturity begins |
How to tell a kitten’s age
- Eyes: closed until 8–12 days; blue until about 6–7 weeks, when the adult color starts to show.
- Ears: folded against the head until about 2–3 weeks, then they stand up.
- Teeth: the first baby teeth (incisors) appear at about 3 weeks, canines at 3–4 weeks. Adult teeth come in from about 3–4 months.
- Movement: crawling at 2–3 weeks, wobbly walking at 3–4 weeks, running and playing from about 5 weeks.
- Weight: about 1 pound (450 g) per month of age up to about 5 months.
Found a kitten? What to do
- Wait nearby for an hour or two – the mother cat is often out hunting.
- If the kitten is cold, in danger or the mother does not return, keep it warm and contact a vet or local rescue.
- Never give cow’s milk. Young kittens need kitten milk replacer from a bottle.
Frequently asked questions
When can kittens leave their mother?
Around 8 weeks at the earliest, and ideally 10–12 weeks, when they are weaned and have had first vaccines.
How much should a 8-week-old kitten weigh?
About 2 pounds (900 g).
When is my kitten an adult?
Cats are considered adults at 1 year. See your cat’s age in human years with the cat age calculator.