Cat Life
Kitten Age Chart: How to Tell How Old a Kitten Is (Week by Week)
To tell how old a kitten is, look at four things together: eyes, ears, teeth and weight. Closed eyes and folded ears mean a kitten is under about two weeks old. Baby teeth appearing means roughly three to four weeks. A steady walker who uses a litter box is usually four to six weeks old. As a rough guide, a healthy kitten weighs about one pound per month of age until around five months.
The kitten age chart below walks through each stage week by week, so you can estimate a kitten's age, know what care they need now, and know when to call a vet. Every kitten develops a little differently, so treat these as typical ranges rather than exact rules.
Kitten age chart at a glance
| Age | Typical weight | Eyes and ears | Teeth | Behaviour |
|---|---|---|---|---|
| Newborn (0–1 week) | About 3–5 oz (85–140 g) | Eyes closed, ears folded flat | None | Sleeps and nurses; cannot keep itself warm; umbilical cord stump falls off in the first days |
| 1–2 weeks | About 4–8 oz | Eyes begin to open (usually blue) | None | Crawls a little, still sleeps most of the day |
| 2–3 weeks | About 8–12 oz | Eyes fully open, ears start to stand up | Tiny front teeth (incisors) start to appear | Wobbly first steps |
| 3–4 weeks | About 12–16 oz | Ears upright | Canine teeth come in | Walks more steadily, starts exploring and can learn the litter box |
| 4–6 weeks | About 1–1.5 lb | Clear, focused eyes | Premolars arrive | Plays, pounces and begins eating wet food |
| 6–8 weeks | About 1.5–2 lb | Eye colour may start changing from blue | Full set of baby teeth | Runs, climbs and plays hard; usually weaned by about 8 weeks |
| 3 months | About 3 lb | Adult eye colour developing | Baby teeth still in place | Very active and curious |
| 4 months | About 4 lb | — | Adult teeth start replacing baby teeth | Teething, chewing and lots of play |
| 6 months | About 5–6 lb | — | Most adult teeth in place | Adolescent energy; ask your vet about spaying or neutering |
Weights are typical for domestic shorthair kittens. Large breeds such as Maine Coons grow faster, and small or underfed kittens can lag behind. For a closer estimate, combine several clues rather than relying on weight alone.
How to tell how old a kitten is: the four clues
1. Eyes
Kittens are born with their eyes closed. The eyes usually begin to open at around one to two weeks and are fully open by about two to three weeks. All kittens start with blue eyes; the adult colour usually begins to show from around six to seven weeks and keeps developing for a few months.
2. Ears
A newborn's ears are folded flat against the head. They begin to unfold at around two weeks and are usually upright by three to four weeks.
3. Teeth
Teeth are one of the most useful clues. Tiny incisors at the front appear first, at around two to three weeks, followed by the longer canine teeth at around three to four weeks and premolars from about four to six weeks. Adult teeth begin replacing baby teeth at around three and a half to four months, and most cats have their full adult set by about six months.
4. Weight and movement
Weigh the kitten on a kitchen scale. Under a pound with wobbly walking usually means three to four weeks or younger; a confident runner who plays and climbs is likely six weeks or older. The “one pound per month” rule is a handy estimate up to about five months.
Kitten development week by week
Newborn to 2 weeks
Newborn kittens depend completely on their mother or a carer for warmth, food and toileting. They cannot regulate their body temperature yet, so warmth is critical. If you find kittens this young without a mother, contact a vet or local rescue straight away; orphaned newborns need round-the-clock bottle feeding with kitten milk replacer, never cow's milk.
3 to 4 weeks
This is when kittens start to look and act like little cats. Ears stand up, teeth appear and they begin to walk, explore and play with littermates. Most can start learning to use a shallow litter box.
5 to 8 weeks
Kittens move from milk to wet kitten food and become confident, playful explorers. This is an important window for gentle handling and socialisation with people. Many vets start the first vaccinations at around six to eight weeks.
3 to 6 months
Kittens grow quickly, lose their baby teeth and become bold and energetic. Your vet will complete the vaccine series and talk to you about microchipping and spaying or neutering.
When to call a vet
Contact a vet promptly if a kitten:
- Is very young and has no mother, or the mother is not feeding them
- Feels cold to the touch, is weak, or cries constantly
- Is not gaining weight, or is losing weight
- Has diarrhoea, vomiting, discharge from the eyes or nose, or breathing problems
- Is much smaller or slower than their littermates
Young kittens can become ill very quickly, so it is always better to call early. A vet can also give you a much more accurate age estimate from a hands-on exam.
Record the first weeks while they last
Kittenhood is over in a few months. The first time their eyes open, the first wobbly steps, the first pounce: these moments are easy to miss and impossible to repeat. Take a photo each week from the same spot and note their weight and one new thing they did. A year from now, it will be one of your favourite things to look back on.
For more ideas, see 50 things to do with your cat, indoor activities for cats and our cat photography ideas. Wondering what treats are safe while they grow? Check any food with our cat and dog food safety checker.
Frequently asked questions
How can I tell how old my kitten is?
Check the eyes, ears, teeth and weight together. Closed eyes mean under about two weeks; baby teeth appear at three to four weeks; and a healthy kitten weighs roughly one pound per month of age until about five months. A vet can give the most accurate estimate.
How much should an 8-week-old kitten weigh?
Most 8-week-old kittens weigh around 1.5 to 2 pounds (about 700 to 900 g). Breed, litter size and nutrition all make a difference.
When do kittens open their eyes?
Kittens usually begin to open their eyes at around one to two weeks old, and their eyes are fully open by about two to three weeks.
When do kittens get their adult teeth?
Adult teeth start replacing baby teeth at around three and a half to four months, and most kittens have their full set of adult teeth by about six months.
When can a kitten leave its mother?
Kittens are usually ready for a new home at around 8 to 12 weeks, once they are eating solid food, fully weaned and socialised with people.
Sources
Age milestones follow widely used kitten development guidance, including Alley Cat Allies' kitten progression guide and the Cornell Feline Health Center. This article is general information, not veterinary advice.
Your kitten won't be little for long
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