How to monitor your kitten’s weight

striped grey kitten

A cat's weight should be regularly monitored.

In order to be sure that kittens grow and thrive, you should regularly monitor their weight. This article will give you guidance on the right weight and show you what you must pay attention to when weighing cats.

How much does a newborn kitten weigh?

A newborn kitten weighs around 100g – the same as a bar of chocolate. With a body length of around 4 inches, it comfortably fits in the hand of an adult human.

Birth weight depends, amongst other things, on the breed of the parents and the size of the litter. Kittens from a large litter are generally smaller and lighter than kittens from a small litter. A Norwegian Forest cat already weighs more than a Siamese, for instance.

The mother’s living conditions during her pregnancy play a role. Stress, illness and poor nutrition can have a negative influence on kittens when they are born. On the other hand, a well-balanced and well-fed cat mother will probably give birth to heavier offspring

As a rule of thumb, the weight of newborn kittens should be around 2 to 3% of the mother's weight. For instance, if the mother weighs 4kg, the kittens should be around 80-120g.

Mother’s milk: important for healthy growth

Kittens are born blind and deaf. They only open their eyes and begin to hear after around 10 to 14 days.

In the first few days of their life, kittens are fully reliant on their mother, who provides them with warmth, protection and nutrition. The mother’s milk ensures that baby cats become big and strong. The first mother’s milk (colostrum) is particularly rich in proteins, enzymes and antibodies and strengthens feline immune systems.

Up to around four weeks of age, mother’s milk is the only source of nutrition. From then kittens can slowly start to adapt to solid food.

Did you know that each kitten has its favourite teat that it always returns to? An intelligent feature of nature, because this avoids conflict between siblings.

You can find special food and accessories for kittens in the zooplus online store.

mom cat with litter © bozhdb /
Up until the age of four weeks, kittens solely feed off mother’s milk.

Weight development in kittens

In the first two or three days after the birth, kittens often lose some weight. However, the weight of kittens should continuously increase afterwards. Up to the age of 12 weeks, they put on an average of 7 to 10 grams per week. When their milk teeth emerge, they often have less appetite and gain weight somewhat slower.

Development is the same for males and females up to around eight weeks of age. The difference between the sexes becomes evident afterwards: small males gain weight quicker than small females.

The following table should offer you guidance as to what weight your kitten should reach at a certain age. All data are of course only average values:

Table: Weight of kittens based on age

Age Development stages Weight in grams  
Birth weight 100
1 week Eyes closed. They spend almost all their time just eating and sleeping. 200
2 weeks Kittens begin to open their eyes. 300
4 weeks The first milk teeth emerge. It is possible to slowly switch to solid food. 500
8 weeks Males gain weight quicker than females. 900
12 weeks The remaining teeth replace the milk teeth. 1700
6 to 8 months Puberty; cats have reached around 80% of their final body weight at the age of 8 months. 4000
12 months The cat is fully grown. 5000

Weighing kittens correctly

In order to keep on top of their weight, you should weigh your cat’s offspring twice a day – ideally always at the same time. You then note down the weight in a recording system that will allow you to quickly observe whether your cat’s weight is stagnating over a long period or even falling.

Ideally use kitchen scales for weighing. Bathroom scales are too imprecise for weighing cats and are therefore not suitable. Put the kitten in a plastic bowl or little cardboard box to be weighed. Make sure that you subtract the weight of the container from the total weight (tare).

Especially in the first few weeks of their life when kittens are still very small and helpless, they shouldn’t be separated from their mother for too long. Hence, keep the scales close to the mother and offspring so that you don’t need to bring the little ones into the kitchen to be weighed at first.

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kitten on scales © c.heusler /
Monitoring weight in cats: best done with the kitchen scales.

Causes of weight deficiency

There can be many causes behind your kittens barely gaining weight: the mother may be producing too little milk or the milk may not contain enough nutrients.

Whilst a cat produces milk for its offspring – this phase is called lactation – it needs 1.3 to 2.5 times more energy from its food. Its protein requirements in particular are increased. Mothers therefore need easily digestible food that is rich in nutrients and provides plenty of energy. Also always provide enough fresh water in a cat bowl.

If the weight is too low: take kittens to the vet

If a kitten gains too little weight or even loses weight, you should see a vet and lose no time. Kittens are highly sensitive creatures and being underweight can soon prove life-threatening.

Parasites such as worms can be responsible for a kitten being underweight. A vet can assist with medication in this case. However, a cat may also be sick and have no strength to suck on its mother’s teat, or it is suffering from an innate disability, such as a cleft palate.

To be on the safe side, you should get baby cats examined by a vet for hereditary diseases after birth.

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