Maine Coon cats do not reach full physical maturation until they are about 4-5 years old. The weight range will vary depending on gender and of course genetics. The accepted size standard for the breed ranges between 11-25lbs, with the males being larger than the females.
This breed grows at double the rate of other domestic cats. They can easily gain 2 pounds per month during their growing cycle. It is important that their weight is monitored and they are not allowed to get too fat or the risk of health problems also doubles. The standards are 15-25lbs for males and 11-20 pounds for females.
Factors That Affect Size
One of the most important things that contribute to the size of a Maine Coon is diet.
A healthy diet that is rich in nutrients and void of things that are not good for them can help a Maine Coon reach its potential size maximum. A healthy diet of a good quality dry mix and some wet food can help insure the proper nutrition that will promote the proper growth.
A bad diet can inhibit the full potential of the cat. A diet that is full of empty calories will put the pounds on, but will not help them maximize their growth potential. You will wind up with a fat cat but not a healthy cat.
Maine Coons are large cats that are muscular, so the next thing on the list of “how to insure maximum growth” is exercise. Maine Coons have plenty of energy and kitten like qualities so they need to be stimulated in their play. They need plenty of toys and someone to play with. Maine Coons that are not exercised regularly risk becoming obese which can cause health issues.
Many owners train their Coons to walk on a leash and harness so that they can be walked like a dog. They enjoy a good walk and it is great exercise not only for the cat but it is also good for you!
If the parents are large in size than it is a much better chance that the kittens will reach maximum size as well. Genetics is one of the most important factors in both weight and length although it does not necessarily mean that a cat will be weigh as much as it's parents. There is always the chance that grandma or grandpa were lighter and have passed on their genes to their descendants.