Most dogs reach their full growth at the age of 12 to 18 months, but this period may last longer on several breeds with big body. There are several breeds to reach their external appearance at the age of 6 months, however, the growth may continue for some more months until their final growth.
Below is a summary of the breeds until their final growth.
Small dog breeds
These kind of dogs seem to reach their building construct within the period from 6 to 8 months, and the final growth of their full size until the age of 12 months.
Average dog breeds
Usually dog breeds that have average body achieve a full body size from age 12 to 16 months, but there are some dogs that reach the final growth after 18 months.
Large dog breeds
This is the group of dogs who grow more slowly than the previous ones. Large dog breed’s body will not reach their body size before 15-18 months of age.Their final body growth is at the age of 22 months.
Huge dog breeds
Dogs breeds like Saint Bernards, Great Pyrenees, Mastiffs, etc need a long time until their final growth.The body’s growth on these races usually is achieved at the age of 18 months,but their full,final growth, with fully formed muscles,is at the age of 2 or 3 years old.
Do not forget that in these statistics the breed of the dog is the most important, often dogs that have 1 or some mixture of genes (of different breeds) have more uneven age when they can reach the full body growth and size in kg.