These charts have been made based on book written by
M. Gerasimova the President of Russian National Club and
International Club of Black Russian Terriers.

Please, remember that the numbers is here are not the absolute, they are approximate and might deviate in some cases - even inside of the same breed.
The individual development always straightly relates to the size of the parents and dogs in their linage and, of course, depends from the quality of nutrition and care provided to a puppy.
However, this chart is helpful in many ways and giving a good idea if you do not have a previous experience with BRTs.