If you have a kitten at home, you may find yourself wondering something surprisingly simple: How much should a kitten weigh?
Maybe your kitten looks tiny compared with another kitten of the same age. Maybe you just brought one home and have no idea whether its weight is normal. Or perhaps you have been weighing your kitten every week and want to know what those numbers actually mean.
The good news is that kittens grow quickly, especially during their first few months.
A kitten’s weight can give you a useful idea of how growth is progressing, but there is no single number that every kitten should reach at every age. Breed, sex, birth weight, nutrition, litter size, and individual development can all make a difference.
Still, a kitten weight chart can give you a helpful starting point.
Kitten Weight Chart by Age
Here is a general guide to average kitten weights during the first several weeks and months:
| Kitten Age | Approximate Weight |
|---|---|
| Newborn | 90–150 g (3–5.3 oz) |
| 1 week | 150–250 g (5.3–8.8 oz) |
| 2 weeks | 250–350 g (8.8–12.3 oz) |
| 3 weeks | 350–450 g (12.3–15.9 oz) |
| 4 weeks | 450–550 g (1.0–1.2 lb) |
| 5 weeks | 550–650 g (1.2–1.4 lb) |
| 6 weeks | 650–750 g (1.4–1.7 lb) |
| 7 weeks | 750–850 g (1.7–1.9 lb) |
| 8 weeks | 850–950 g (1.9–2.1 lb) |
| 10 weeks | Around 1.2 kg (2.6 lb) |
| 12 weeks | Around 1.4–1.5 kg (3.1–3.3 lb) |
| 16 weeks | Around 1.8–2.0 kg (4.0–4.4 lb) |
| 20 weeks | Around 2.1–2.2 kg (4.6–4.9 lb) |
These numbers are general reference points, not strict targets. Different kittens can grow at different rates and still be healthy.
For example, a study of more than 1,300 kittens found average weights of about 1.02 kg at 8 weeks, 1.22 kg at 10 weeks, 1.45 kg at 12 weeks, and 2.18 kg at 20 weeks. There was also noticeable variation between individual kittens.
How Much Should a Newborn Kitten Weigh?
Newborn kittens are surprisingly small.
A typical newborn kitten may weigh roughly 90 to 150 grams, although individual birth weights can fall outside that range.
The first few weeks are a period of extremely rapid growth. According to the Merck Veterinary Manual, normal kitten birth weight is around 90–100 grams, and kittens may gain approximately 50–100 grams per week during their first three to four months.
This is one reason weighing very young kittens can be useful.
A kitten that is growing steadily is giving you much more information than a single measurement taken on one particular day.
How Much Should a 2-Week-Old Kitten Weigh?
A 2-week-old kitten commonly weighs somewhere around 250–350 grams.
At this age, kittens are still very dependent on their mother or an appropriate milk replacement if they are being hand-raised.
Their eyes are beginning to open, their ears are developing, and they are becoming more active.
Weight can help provide context, but it should not be considered on its own. A kitten’s overall development and behavior matter too.
How Much Should a 4-Week-Old Kitten Weigh?
At around four weeks, many kittens weigh approximately 450–550 grams.
This is an interesting stage because the kitten is beginning to look much more like a miniature cat.
Kittens around this age are becoming more coordinated, starting to explore their surroundings, and gradually becoming more independent.
The exact number on the scale can vary. What matters is that the kitten is continuing to grow rather than focusing on whether it matches a single number perfectly.
How Much Should a 6-Week-Old Kitten Weigh?
A 6-week-old kitten may weigh approximately 650–750 grams.
By this stage, kittens are usually much more active. They can walk and play confidently, and they are becoming increasingly interested in food.
A published study found an average weight of about 0.69 kg for 6-week-old kittens, with individual variation around that average.
So if your kitten weighs somewhat more or less than this, that does not automatically mean something is wrong.
How Much Should an 8-Week-Old Kitten Weigh?
An 8-week-old kitten often weighs around 850–950 grams, or roughly 1.9–2.1 pounds.
Another large study found an average weight of approximately 1.02 kg at eight weeks, demonstrating why different charts may show slightly different numbers.
PetMD gives a similar general range of about 850–950 grams for an 8-week-old kitten.
This is also around the age when kittens are becoming increasingly independent and developing their coordination and eating habits.
If you are trying to determine whether your kitten is approximately eight weeks old, weight can provide a clue, but it should not be the only thing you use.
Is a Kitten Supposed to Gain Weight Every Week?
Generally, kittens should be growing during their early development. Generally, kittens should be growing during their early development. According to the Merck Veterinary Manual, kittens may gain roughly 50–100 grams per week during their first three to four months.
The important word is trend.
A kitten that weighs 700 grams one week and 750 grams the next is showing a different pattern from a kitten that suddenly loses weight.
That is why keeping a simple record of your kitten’s weight can be useful.
You do not necessarily need an elaborate chart. You can simply record:
- Date
- Kitten’s age
- Weight
- Any noticeable changes
Over time, those measurements create a much clearer picture than one isolated number.
Does Kitten Weight Depend on Breed?
Yes.
Not every kitten is going to follow exactly the same growth pattern.
A kitten that will eventually become a large adult cat may grow differently from a smaller cat. Even kittens of the same breed can have different growth patterns.
Sex can also make a difference as kittens get older.
In a study of kittens between 6 and 20 weeks, males were generally heavier than females at several of the older age points, particularly from around 10 weeks onward.
This is another reason a kitten weight chart should be treated as a guide rather than a rule.
Can You Tell a Kitten’s Age by Its Weight?
Sometimes.
Weight is particularly useful when trying to estimate the age of very young kittens.
Research has found a strong relationship between age and body weight during the neonatal period. However, the relationship becomes less reliable as kittens get older. The researchers concluded that weight was useful for estimating age through approximately 10 weeks, but other characteristics should be considered after that point.
So if you have a tiny kitten and are trying to figure out how old it might be, weight can be one piece of the puzzle.
You can also look at development, teeth, eyes, ears, movement, and behavior.
For more help with that, see our guide on How to Tell How Old a Kitten Is.
What If My Kitten Weighs More or Less Than the Chart?
Don’t panic because of one number.
A chart is useful for comparison, but it cannot tell you everything about an individual kitten.
For example, two kittens of exactly the same age can have different weights and still be developing normally.
The more useful question is often:
Is my kitten growing steadily?
If the kitten is eating normally, active, developing expected behaviors, and gaining weight over time, those observations provide useful context.
On the other hand, if a young kitten is losing weight, consistently failing to gain weight, refusing food, appearing weak, or showing other concerning changes, it is a good idea to speak with a veterinarian rather than relying on an online chart.
How Often Should You Weigh a Kitten?
For very young kittens, regular weighing can be helpful because their weight changes quickly.
A kitchen scale that measures in grams can make small changes easier to notice than a regular bathroom scale.
Try to weigh the kitten under similar conditions each time and record the result.
You do not need to become obsessed with tiny fluctuations.
The goal is simply to notice the overall direction.
Growing steadily is generally more informative than hitting an exact number on an exact day.
What Weight Should a Kitten Be at 3 Months?
At around 12 weeks, a kitten may weigh roughly 1.4–1.5 kilograms, or around 3.1–3.3 pounds.
However, this is an age when individual differences become increasingly noticeable.
A scientific study found an average weight of about 1.45 kg at 12 weeks, with substantial variation among individual kittens.
That means a kitten weighing somewhat above or below the average is not automatically outside a healthy range.
What Weight Should a Kitten Be at 4 Months?
At around 16 weeks, many kittens weigh somewhere around 1.8–2.0 kilograms, or approximately 4–4.4 pounds.
Again, this is only a reference point.
Growth is particularly rapid during the first few months. The Merck Veterinary Manual notes that kitten growth begins to slow later in development, with growth generally completed within roughly 200–220 days for many domestic cats.
Large breeds can follow a different timeline.
When Should You Be Concerned About a Kitten’s Weight?
A kitten’s weight deserves closer attention when the overall pattern changes.
For example, it may be worth contacting a veterinarian if your kitten:
- Is losing weight
- Stops gaining weight
- Is not eating
- Seems unusually weak or inactive
- Has persistent vomiting or diarrhea
- Has difficulty breathing
- Shows other sudden changes in behavior or health
A weight chart cannot diagnose the reason for a problem.
It can simply help you notice that something has changed.
Kitten Weight Is About More Than One Number
It is tempting to look at a kitten weight chart and immediately compare your kitten with the number in the table.
But kittens are individuals.
One kitten may be small and steadily growing. Another may be larger from the beginning. Some gain weight faster during one period and then slow down.
That is why the most useful thing you can do is watch the pattern of growth rather than expecting your kitten to match a chart perfectly.
If you already know your kitten’s age, you can also compare its weight with other developmental information.
Our Kitten Age Chart: How Old Is My Kitten? can help you connect age with typical development.
And if you are trying to understand how quickly kittens grow overall, our guide on How Fast Do Kittens Grow? can help you look at the bigger picture.
The Simple Way to Use a Kitten Weight Chart
Think of a kitten weight chart as a reference, not a report card.
Use it to get a general idea of where your kitten’s weight falls for its age.
Then look at the bigger picture:
Is your kitten growing? Is it active? Is it eating? Is it developing normally?
Those questions are often more useful than asking whether your kitten weighs exactly the number listed in a chart.
Kittens grow incredibly quickly during their early months, and watching that transformation can be one of the most rewarding parts of having one.
A few numbers on a scale can help you follow that journey, but they are only one part of the story.