Is determined by the ideal height at the withers and desirable ratios between the height and the measurements of the various parts of the external anatomy.
The ideal height for a dog is 68cm (lower than 60 cm is unacceptable).
There is no maximum height limit in this breed standard. As explained before, the height limit is reached when the dog does not have the desired Boerboel movement.
There is a restriction on minimum height and the reason behind this is extremely significant. When you begin to breed large breed dogs that are smaller than desired, the resulting offspring usually quickly decrease in size. Then, trying to get size back by breeding these undersized dogs is usually very hard. When breeding Boerboels, you should try to breed to males over 66cm at the withers to avoid this possible problem.
The ideal height of a bitch is 61cm (lower than 55 cm is unacceptable).
Once again, there is a minimum height restriction for the same reason as mentioned above. Females are noticeably smaller because we want a clear difference between the sexes. Also, like the males, the maximum height is reached when movement is sacrificed. As far as breeding goes, females should look like females and, as a rough guideline, be smaller than the male they are being bred to.