Cat Breeds
When Do Maine Coons Stop Growing? Growth Timeline & Size Guide
When determining when do Maine Coons stop growing, most cats reach full adult maturity between 3 and 5 years of age. Unlike standard domestic cats that reach full adult size by 12 to 18 months, Maine Coons are a slow-maturing breed whose skeletal frame, muscle mass, and dense coat require 36 to 60 months to complete development. Skeletal length and height largely finalize around 2 to 3 years of age, while muscle density and chest width continue filling out until age 5.