Ever looked at your furball lounging on the couch and wondered, "Is my cat just fluffy, or is there a bit too much kitty to cuddle?" You're not alone. With treats around every corner and snooze marathons a daily occurrence, it's easy for our feline friends to pack on a few extra pounds. But how do you tell if your cat has crossed the line from pleasantly plump to overweight? Don’t worry; we're about to unravel the mystery of feline fitness.

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  1. How Much Should My Cat Weigh
  2. How to Calculate Your Cats fBMI Manually
  3. Is My Cat Overweight
  4. Causes of Weight Gain in Cats
  5. What to Do If My Cat Is Overweight
  6. FAQs
  7. Conclusion

How Much Should My Cat Weigh

Deciphering your cat's ideal weight can sometimes feel like trying to solve a puzzle with missing pieces. Knowing how much your cat should weigh is not as simple as looking at a number on a scale. Instead, it involves observing your cat's body shape and behavior and sometimes using tools like an overweight cat chart or a feline Body Mass Index (BMI) calculator for guidance.

Now, in the next section, we will give some general guidelines for how to know if your kitty is on the chubby side. So if you don’t want to do the math, then skip to the next section, because first we will discuss how to work out your cat’s BMI at home.

Yes, just like humans, cats have a BMI. And we will tell you how to work it to your cat’s perfect weight. There are several different charts to help you assess your cat’s body condition. But there is one way to know exactly how much a cat should weigh.

Enter the realm of feline Body Mass Index (fBMI), a fancy way to figure out the fitness of your feline friend. A study from the Japanese University of Veterinary Medicine has thrown us a lifeline in the form of a new diagnostic tool that’s purr-fect for assessing weight and obesity in cats as effectively as possible.

According to the study, a healthy fBMI for cats ranges between 24.6 and 40.3, with anything over 28.0 waving a red flag for overweight or obesity.

How to Calculate Your Cats fBMI Manually

Understanding if your feline friend is at a healthy weight is crucial, and you can actually do a little math yourself to find out their fBMI (feline Body Mass Index). Forget the scales; this is all about proportions. Here's how you can calculate your cat's fBMI with just a measuring tape and some simple arithmetic.

Step 1: Gather Your Tools and Cat

You'll need a flexible measuring tape. Ensure your cat is standing and looking straight ahead — their most dignified posture.

Step 2: Measure the Rib Cage

Wrap the measuring tape around your cat's rib cage, right where their 9th rib is located — near the front legs. Write down this circumference.

Step 3: Measure the Leg Length

Now, find the length of your cat's hind leg from the knee to the ankle — this is called the lower back leg length. Take note of this measurement as well.

Step 4: Apply the Measurements to the Formula

With your cat's measurements in hand, you'll plug them into the fBMI formula. This is how to do it:

  • Take the Leg Length – our number was 20 cm – and multiply it by itself and then by 0.706. If we use our example, it’s like saying 20 cm x 20 cm x 0.706. This will give you a special number.
  • Then, you take that special number and subtract the Rib Cage Circumference from it two times. So, if our special number was 100, we would do 100 - 30 cm - 30 cm.
  • What you get after that is your kitty's fBMI. It's a number that tells us if our kitty could be eating too much or if they’re just right!

Step 5: Understanding the fBMI Value

Once you've done the calculation, compare your cat's fBMI to these ranges to determine their weight category:

  • Underweight: fBMI less than 15;
  • Normal Weight: fBMI between 15 and 29.9;
  • Overweight: fBMI between 30 and 42;
  • Obese: fBMI over 42.


Let's say your cat has a rib cage circumference of 35 cm and a lower back leg length of 5 cm. Plugging those into the formula gives:

Do the math, and you'll have your cat's fBMI. From there, you can see where your cat stands on the weight spectrum.

Why This Matters

This formula is rooted in research and designed to give a more accurate indication of a cat's body condition than weight alone, as weight can be misleading due to variables like breed and size. However, the fBMI is just a starting point — for a comprehensive health assessment and weight management plan, a vet visit is always recommended.

Is My Cat Overweight

The reality is, there's no one-size-fits-all answer to questions like "Is 13 pounds overweight for a cat?" or "Is 20 pounds overweight for a cat?" Each feline is unique. Yet, general guidelines suggest that many domestic cats should weigh between 8 and 10 pounds, with larger breeds naturally weighing more.
The numbers climb higher, and if you find your cat tipping the scales at 16 pounds or more, it's likely your feline friend is in the overweight category, unless they belong to a larger breed.

So, to help you tell if your cat is overweight, you can look for a few telltale signs. An overweight cat may have:

  • A noticeable paunch or tummy hanging between its hind legs;
  • A lack of a visible waistline when viewed from above;
  • And you may have difficulty feeling its ribs when you gently run your hands along its side.

If you notice your cat snoring more than usual or an overweight tabby cat struggling to groom itself properly, these can also be clues pointing to excess weight.

The weight range for cats can vary significantly based on breed, age, and sex. For example, a Siamese cat typically weighs less than a Maine Coon. So, while 12 pounds might be overweight for a delicate Siamese, it could be perfectly healthy for a sturdier breed. Similarly, 15 pounds might seem high, but for some large breeds, it's a normal weight. However, if a smaller domestic cat hits 15 lbs or more, it's often a red flag that your feline may be carrying too much weight.

It's not unusual for an overweight cat to exhibit an insatiable hunger. If you're thinking, "My cat is overweight and always hungry," it might be time to reassess their diet and consult with a vet for underlying issues like diabetes. Having a Pet Camera to monitor your cat’s eating habits and activity levels can help you gather crucial information to tell your vet.

Some cats, like an overweight hairless cat, might show weight more obviously due to the lack of fur, while an overweight Siamese cat, known for its svelte lines, might make it more apparent when those lines start to blur.

A cat body weight chart can also be a useful visual aid. These charts provide a visual comparison of body shapes ranging from underweight to obese. They give you a general guideline to assess your cat’s body weight, while using the cat BMI calculation above can give you a more exact assessment.

It's critical to remember that overweight cats can face various health issues, from diabetes to joint pain. To ensure your feline companion lives a long, healthy, and active life, keep an eye on their body condition and consult with your vet for a personalized plan to keep your cat in tip-top shape.

Causes of Weight Gain in Cats

Let's dig into what might be tipping the scales for our feline friends.

Sneaky Snacks and Treat Treasures

Just like us, cats can put on extra pounds if they're eating more snacks than they need. Sometimes, those big, pleading eyes can convince us to give just one more treat, which adds up over time.

The Couch Potato Life

Cats are natural-born loungers, and sometimes they take relaxing to an extreme. If they're not chasing feathers or pouncing on toys, they're not burning off any of the energy from their meals.

Mystery Meals

If your kitty isn't the only animal in the neighborhood, they might be sneaking extra meals somewhere else. Some cats have a secret double life where they get fed by other families too!

Growth Spurts and Golden Years

Growing kittens and older cats may gain weight for different reasons. Kittens might be building up their strength, while senior cats may slow down and not play as much as they used to.

Invisible Invaders

Sometimes, weight gain is caused by little invaders we can't see, like sneaky worms. These parasites can make a cat's body think it's not getting enough food, so they eat more and more.

A Change in the Weather

Cats might eat more during certain times of the year, like when it’s colder and they need extra energy to stay warm. Or maybe they just love the taste of seasonal treats!

Mysterious Metabolism

Each cat is different, and their metabolism—how they burn food for energy—can vary. Some burn it off quickly, while others might keep it as a cozy layer of fat.

Underlying Health Hiccups

Various health issues can sneakily contribute to weight gain. Metabolic disorders, such as hypothyroidism, can slow down a cat’s metabolism, making it easy for weight to creep on. Diabetes is another condition that can influence weight gain, as can certain medications that might lead to increased appetite or water retention.

Soothing the Soul

Sometimes, when cats feel stressed or upset, they eat to feel better, just like people might. A new pet in the house, a move to a new home, or even changes in the family can lead to comfort eating.

Tick-Tock Goes to the Biological Clock

As cats get older, their bodies change, and sometimes those changes mean they gain weight more easily. Think of it as their inner clock changing the schedule of their body’s needs and activities.

Understanding why cats might gain weight is important because we love our purring pals and want them to be as healthy and happy as possible. By keeping an eye out for these causes, we can help our cats maintain their best catwalk shape!

What to Do If My Cat Is Overweight

Discovering that your feline friend tips the scales into the overweight category can be worrisome, but there are effective steps you can take to help them slim down to a healthier size.

  • Craft a Custom Diet Plan: Consult with your vet to design a tailored diet that provides balanced nutrition while reducing calorie intake. The right diet is essential for healthy weight loss in cats.
  • Engage in Active Play: Increase your cat's physical activity with toys and games that encourage movement, such as laser pointers or interactive feeders that make your cat work for their food.
  • Regular Weight Checks: Monitoring your cat's weight regularly helps track progress and ensures the weight loss is gradual and healthy. Sudden weight loss can be as dangerous as being overweight.
  • Strategic Feeding: Implement a controlled feeding strategy, breaking down meals into smaller, more frequent portions to manage hunger without overeating.
  • Seek Expert Guidance: The Petcube Emergency Fund offers 24/7 access to online vets who can assist you in monitoring your cat's weight, spotting signs of underlying health issues, and overseeing your cat’s weight loss journey. As a reader of this blog, you can take advantage of a special 27% discount here to ensure you have the resources you need.

Remember, weight loss should be a gradual process. A slow and steady approach ensures your cat remains healthy and happy during their transition to a slimmer lifestyle.


Is my cat overweight even if it's not overeating?

If your cat is overweight without overeating, it could indicate a low metabolism or a medical condition. It's important to consult your vet to rule out any underlying health issues.

What's the best cat food for overweight cats?

The best food for overweight cats is a high-protein, low-carbohydrate diet that's low in calories but still nutritionally complete. Consult with your vet for a recommendation that's tailored to your cat's specific needs.

Does being overweight affect my cat's lifespan?

Yes, overweight cats can have a shorter lifespan due to the increased risk of diabetes, liver problems, and joint issues. Maintaining a healthy weight is crucial for a longer, happier life for your feline friend.


Tackling your cat's weight issues is vital for its well-being. With the right diet, exercise, and vet advice, you can guide your cat back to a healthy weight, ensuring it lives a long, joyous life by your side.

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