Weight is a fairly good indication of health in both human and animal newborns. It can be particularly important for a kitten or a puppy that has lost their mother or, for some reason or another, can’t feed by themselves.
Kittens grow very fast during the first twelve weeks of their lives because they have to quickly be prepared to handle the world – and the potential attack of larger predators or other animals they might have to battle for food (at least in the wild).
If you ever find a kitten without a mother and you want to take care of them, the best way of doing so would be to guide your progress based on a kitten weight chart. Read on to find out more!
Kitten weight chart
Naturally, the weight of a kitten is an important factor, but there are lots of other aspects to look for as they grow, such as whether they open their eyes or ears normally if they start looking for food on their own, and how they communicate with the other cats that might share their living space, how they’re ‘going to the bathroom’, and so on.
You can find several guidelines on what the ideal weight of a kitten should be at a specific time during the first twelve weeks of their life:
| Kitten’s age | Ideal weight |
| 0-6 days | 3-7 ounces |
| 1 week | 5-10 ounces |
| 2 weeks | 8-14 ounces |
| 3 weeks | 10 oz to 1.1 pounds |
| 4 weeks | 12 oz to 1.3 pounds |
| 5 weeks | 14 oz to 1.6 pounds |
| 6 weeks | 1 to 1.2 pounds |
| 7 weeks | 1.2 to 2 pounds |
| 9 weeks | 1.4 to 2.5 pounds |
| 10 weeks | 1.6 to 3 pounds |
| 11 weeks | 2 to 3.2 pounds |
| 12 weeks | 2.3 to 4 pounds |
These are general guidelines, so naturally, there can be differences of up to 50 or even 100 grams for each kitten age. What matters most is how the kitten’s weight progresses during the first one to three weeks of their life. Once they are generally fine after that and you do not have to feed them as often, they’ll start putting on weight with more ease.
Do consider that even when they are 12 weeks of age, kittens aren’t really prepared to fend for themselves.
Think of a situation where your kitten might be left in the woods – would they be able to find food and hide so that they aren’t attacked by other animals? Probably not, at least not yet. An age such as 16 to 20 weeks would be more suitable for that.
When can kittens be underweight?
Kittens can actually be born underweight if their mother was sick during pregnancy or they maybe had no access to enough quality food. Animals that are born with congenital disabilities are also less likely to feed properly, so they always run the risk of becoming underweight.
There’s also the possibility that the queen doesn’t have enough milk for everyone, and if she gave birth to a quite large litter, some of the smaller kittens might not have access to food, as much as they might fight their brothers and sisters.
Additionally, kittens can be orphaned. Their mother might have gotten into an accident while out searching for food, or she might have simply abandoned them. Although quite rare, cases where a mother leaves her kittens can still happen.
During the first week of their life, kittens are entirely dependent on the queen or, if you’re the one caring for them, you. You need to feed a kitten once every two to three hours during the first week of their life, so it involves a high degree of commitment and attention.
Why weighing your kitten matters
Kittens that might have lost their mothers or whose mothers aren’t producing enough milk for all of them need to be weighed on a regular basis – ideally every day.
As you might have noticed from the chart above, kittens tend to put on the most weight during the first few weeks of their life, and this is actually essential for them to experience a healthy development later on.
Weight loss might be a sign of a health condition, whether that be digestive distress, infections, parasites, or anything else, including Fading Kitten Syndrome.
When should you take your kitten to the vet?
It depends on a couple of factors. The first is your kitten’s age. If your kitten is less than 3 weeks of age and you notice a decrease in their weight, veterinary assistance is required almost immediately. Time is of the essence in this case.
If the kitten is older, such as 12-weeks or 16-weeks-old, you might be able to wait for one to two days before taking them to the vet clinic. However, you should base your decision on the symptoms that the kitten shows and whether they are rapidly losing weight either way.
Depending on what condition the kitten might have developed, they might not only be losing weight but also precious fluids. In cats, dehydration is a real problem as they don’t drink a lot of water on their own anyway, so if your kitten starts vomiting or experiencing diarrhea, take them to the vet as soon as possible.
