The breed of your cat is one of the biggest factors that will affect how long they grow.
Male cats tend to be slightly larger than female cats, and they may take a little longer to reach their full size.
Providing your cat with a healthy diet that is high in protein and taurine will help them grow to their full potential.
Exercise is also important for cat growth. Exercise helps to build muscle and bone mass, which will help your cat reach their full size.
Any health problems that your cat may have can affect their growth. If your cat is sick or injured, it may delay their growth.
Ultimately, the genes that your cat inherits from their parents will play the biggest role in how long they grow.
It's important to remember that there is always some individual variation in cat growth. Some cats may reach their full size sooner or later than others.