How long does it take for a Maine Coon to fully grow?

Mainecoons are most popularly known for their huge size as they grow up to be really big, fluffy with furry Maine’s. I’m sure you confused and you thinking why is your Maine coon still so small and how long will it take to fully grow?

Maines generally take 4 years to fully grow while some are fully grown at 3 years. The time taken for a Mainecoon to fully grow depends on a variety of factors such as diet, health issues, genetics and nature. That said, these cats do grow very slowly and it takes a lot of time for them to be fully grown as they have a lot of growing to do since when grown they weigh between 12-25 pounds.

These cats do take longer to grow compared to normal domestic cats and will eventually fully develop if their health is right and if they are fed the correct portions of nutritious foods.

Many Mainecoon owners often are stuck in a situation where they aren’t seeing their cats grow. These types of Mainecoons are most probably hybrids, usually mixed with other breeds, and don’t get very big in size neither do they develop the fluffy coat and Maine’s of a purebred Maine cat. In some cases, they will resemble purebreds but won’t be so defined.

These hybrids are often sold at a lower price or the breeders deceive people and sell them as purebred. Therefore when buying Mainecoon kittens look for a reputable breeder that is well known and won’t rob you. If not you will be stuck with a hybrid Maine that doesn’t even resemble a Mainecoon anyway.

Why does it feel as if my Mainecoon isn’t growing?

Owning a big cat can be very exciting and interesting especially if it’s your first big domestic cat and you anticipating its growth. But why does it feel as if my Maine is just not growing?

Rest assured as Mainecoons take a long time to fully grow.

Mainecoon cats grow at a steady set pace and sometimes their growth can’t be seen because it’s so slow. Therefore it’s best to develop a growth chart to track the cat’s weight and height per month. With these stats, you will be able to clearly see if the cat is making progress or not.

If your Maine is well-fed, healthy and is a purebred than its only a matter of time till you have a gently-giant in your own home.

However in very few cases you will find that Mainecoons just don’t get big. They remain below 10 pounds and show no signs of growth. This is most often in female Maine’s and the reason is still unknown.

Maine Coon Growth Chart.

  • Get a suitable scale, don’t use a human scale as it wont provide accurate results. You can use a baby or postage scale which works well. Make sure to use the same scale at every weighing as some scales may need calibration.
  • Measuring tape, something flexible and easy to use to check height, length and waist. An household or clothing tape will work well.
  • Get a book to record changes and the results each month. Some people may prefer to have a digital notepad which works equally well.
  • Every month on a particular day examine the cats body weight, length and height. Make sure you record the data and create a graph to see the actual results. You can also get copy of a graph from the net and add the recordings to it.
  • Its important to note that when measuring don’t measure the cats fur but rather make your way through the fur to the vital areas in which you are going to measure from. This will produce more accurate results.
  • Always weigh the cat before any meals preferably in the mornings. This will prevent the food weight from interfering with the accuracy of the results.

Factors that affect the growth of a Maine cat.

There are many factors involved in the growth and development of Mainecoon cats. These factors could either promote healthy growth or could stunt their growth causing them to be undersized and under-nourished.

Gastrointestinal Parasites

Intestinal parasites such as roundworms or tapeworms can really stunt a Mainecoon cat’s growth as they will steal the required nutrients. These parasites live in the gut and every time the cat eats they feed off the same food. This will make the cat feel more hungry and they will require more food but still, won’t be satisfied. An infestation of these worms can cause a major calorie deficit causing growth and development to halt.

Signs of worms in Mainecoon cats include:

  • Increased appetite
  • Evidence of partial worms in their faeces and around the anus.
  • Excessive cleaning or grooming around the bottom.

If your Maine has worms consult with your vet for proper medication such as de-wormers. This medication can be given orally or by injection and within 24 hours the worms will die. In some extreme cases a second dosage of medicine will be required 3-4 weeks after.

Once the worms are gone, the cats body will get rid of the dead worms and the body will heal itself causing growth and development to continue.

Insufficient food

Some first-time Maine owners often underfeed their cats since they think Mainecoons are the same as any other cat. The truth is that Maine’s are much bigger in size and they do require a lot more food to grow and develop. They require about 25-30 calories per pound of body weight to maintain their muscles and nourish their bodies. Maine kittens under 1 year require even more food than normal since they do get hungry more often due to the developmental stages they are going through.

If the food isn’t enough the cats body will remain in a deficit and the cats growth will stunt. Continuous lack of food will cause the cats body to break down fat and muscle which will be used for energy. This will result in the cats weight decreasing and their growth will halt until the proper nutrition is met. Checkout out my previous article that discusses the right amount of food a maine coon requires.

Another way that nutrition can hold a Mainecoon from growing is if the cat isn’t fed the right foods that contain the required macro-nutrients and minerals to promote growth.

The right diet for Maines should contain

  • Protein – 60% of identifiable protein such as chicken, meat or turkey.
  • Fats and omega 3 & 6 – 20-30% of healthy fats.
  • Carbohydrates – 10-15%

When searching around for the best food make sure you do your research and go with familiar and reputable brands. Stay away from those foods that contain starch, fillers and artificial ingredients. You can also include wet, dry and raw food in the cats diet to provide variety and balance.

Health issues

There are several health issues associated with Mainecoon cats but the most common abnormalities are

  • Hypertropic Cardiomyopathy, which is a hereditary disease that affects the cats heart causing it to thicken, decreasing the hearts efficiency.
  • Hip dysplasia is a degenerative disease that causes malformation in the cats hip joint.
  • Polycystic kidney disease is an inherited condition in cats that causes cysts in the kidney. This is very common and can be fatal if not treated.

These health issues especially kidney disease cause a variety of symptoms that negatively affect a cats growth. Some of the most common symptoms are

1. Decreased appetite

2. Nausea

3. Vomiting

4. Weight loss

5. Lethargy

6. Thirst and frequent urination

If your cat is showing any signs of sickness such as lack of appetite, decrease in weight or cannot withhold food then speak with your vet to get a proper diagnosis so that treatment can be administered immediately.

Often these health issues go on for years unnoticed and eventually its too late to be treated. Its always important to track your Maine’s growth and weight to make sure the cat is developing, if the cat shows no signs of growth and development over a period of time seek medical advice immediately.

The Maine’s lifestyle

The type of lifestyle a Mainecoon live is very important in their growth and development. What I’ve noticed is that cats that are very energetic and active burn much more energy and calories in that lifestyle. Therefore not enough nutrient is preserved for the body to promote growth and strengthening.

Un-neutered and un-spayed cats also tend to use up most of their energy on being aggressive, fighting and roaming. These cats are normally urged to satisfy their sexual desire in which they try to run away from home in aims to find a mate. Another important aspect is the process of escaping, the amounts of failed attempts, the amount of vocalization and the eradic behavior.

All these are contributing factors that uses up most of the cats energy source. Therefore little to no nutrients are kept for growth and development.


Genetically purebred Mainecoons are very big and grow pretty well through the years. These cats are big-boned and muscular with very long hair which makes them look even bigger. The purebred Mainecoon weighs around 15-25 pounds while some males exceed the 25-pound weight and some females weighing lower than 15 pounds. These cats do take longer to grow but within 3-4 years they will be fully grown and developed.

The other kinds of Mainecoons known as hybrids. These cats contain a mixture in their genetics and aren’t purebreds. They deviate from the original appearance of Maines and are normally smaller. Even if time passes they won’t grow any further once they reached a certain level of development.

Therefore it’s important to do a little research before you adopt or buy a Maine coon as some breeders known as backyard breeders will sell hybrids as if they are purebreds.

There are ways to identify an original purebred Maine coon by looking for certain traits.

  • Maines are large whether they are still kittens or adults they are way bigger than a regular cat. So don’t be fooled into adopting a small kitten with the aim of it growing bigger.
  • Thick silky hair and fur tufts around their paws.
  • The cats body is rectangular in shape.
  • Maine’s ears are lynx-like shape with tufts of hair at the tips.
  • Big and wide snout.
  • Appears to have a large square jaw which gives a distinctive shape to their facial appearance.
  • Very social by nature and love water.
  • Known as the gentle-giants these beauts are very friendly soft and affectionate, which is a formidable trait that you can use to identify them.

Do all Maines grow big ?

Now that we know that there are different types of Mainecoons namely purebreds and hybrids. The big question is if all Mainecoons grow that big?

Not all Mainecoons grow big. Some female Maines are known for being way smaller than the average in weight around 10 pounds even if they are purebreds, while some males may grow extremely larger reaching 30 pounds. However mostly Maine mixes or crossed will not grow big and will be substantially smaller than a purebred.

This is caused by the mixture of the genetic material of other breeds therefore the original Mainecoon gene pool cannot be preserved. So a mixed Maine coon will show some traits of being a Maine as well as some traits of the other breed. This causes a modification in their appearance and size resulting in a smaller-sized cat with some shared Mainecoon traits.

In some cases an hybrid Maine coon can actually grow to the same size of a purebred Maincoon. As it depends on the other type of cat breed which was used in the cross.

How big do half Mainecoons get ?

Half Mainecoon cats refer to the type of cats that are produced when Maine’s are crossed with another breed. These cats can grow really big or remain average size depending on the type of breed that was used in the cross.

Half Maincoons can grow between 10-25 pounds when fully grown. The size ultimately depends on the other cat breed that was used in the cross. For example, if a Mainecoon was mixed with another big cat such as a Ragdoll or a Norwegian forest cat then the kittens produced are going to be equally big in size once fully grown.

In the same way, if the Mainecoon was crossed with an averaged size cat then the kittens produced can either be small or average and in some cases much bigger or equally big as Maine’s.

What is a healthy weight for Mainecoons ?

Mainecoons are the largest known domestic cats and for this reason, they are at risk for obesity and other weight-related issues but due to their long hair it’s very difficult to check whether the cat is overweight or not.

A healthy weight for Mainecoons depends on their height, fat percentage, and age. Some may weigh as little as 8-10 pounds while others may be perfectly healthy at 20 pounds. Your vet is the best person to examine the cat and calculate its ideal weight.

However there are several ways that you can use to check if the cat is overweight.

  • Stroke your cats side and back as you should feel their ribs and spine. If you cant than your cat is probably overweight, And if the cats ribs protrude than the cat is probably underweight.
  • Look at the cat from above. The area between the ribs and hip should curve inwards creating a smaller waist. If there is no waist the cat may be overweight.
  • Examine the base of the cats tail. You should be able to feel the bones near the tail. If you cannot then cat may be overweight.

Mainecoons weight and development

  • Newborns – (0,2-0,4 pounds)
  • 1 month – (1,3-1,8 pounds)
  • 6 months – (8-10 pounds)
  • 1 year – (10-12 pounds)
  • 2 years – (15 pounds)

These are just average weights of Mainecoons and are not the exact weight a Maine coon will reach every stage of development. What I’ve noticed is that males tend to be bigger compared to female Maine’s while some Maine coons just never grow pass a certain point. This is purely nature and its also possible with purebreds as well.

For information on maine coons dental development checkout my previous article.

Related Questions

  1. Do Mainecoons have 6 toes? No Mainecoons don’t have 6 toes however some do. This is a medical condition called polydactylism. This condition is caused by a genetic mutation that results in extra toes.
  2. Do Mainecoons grow slowly? Yes, maines are known for their slow growth and sometimes the growth is not seen since the process is so subtle. For this reason, a growth chart is recommended.
  3. What do Mainecoons die from? Hip dysplasia, cardiomyopathy, kidney failure, and health issues related to obesity such as diabetes and arthritis.

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