English Mastiffs are considered a GIANT breed. Although they are not the tallest breed, they are considered the largest because of their bulk. Like people, there will be some variation in their weight and height and no breeder can guarantee exactly how tall or how heavy your pup will become. The best way to get a good “guestimate” of what your pup will end up looking like is to take a close look at the relatives in your pup’s line.
English Mastiffs grow fast, but do not finish growing for several years. Their growth spurts resemble teeter-totters. First the hind end raises up, then their front. It can take them up to 2 ½ years to reach their final height. Many do not reach their full weight until 4-5 years.
In general, you can expect an English Mastiff to approximate the standard set by the American Kennel Club (AKC). According to that standard, a female should reach a height of at least 27 ½ inches at the shoulder, and a male should reach a height of at least 30 inches at the shoulder.
Just as there are variations in height, there are variations in weight. The average female mastiff weighs 120-170 and the average male weighs 160-230. Some will weigh more, and some will weigh less (I have yet to find one who weighs less yet, but I’m fairly certain they are out there!)
It should be pointed out that the “standard” for the English Mastiff varies between different nations. What is most important (at least to us) is that you choose your pet based on the qualities you are looking for. Some people like the super tall and somewhat Dane-like appearance. Others like the heavy, large boned mastiffs with huge heads. Some like medium sized mastiffs that are a bit higher in energy and more athletic. Take a good look at the mature relatives and the qualities they offer. This will give you the best shot at picking a pup that will grow up looking the way you expect.
JUST FOR FUN: The largest, recorded English Mastiff was Zorba. He was almost 8 feet long from nose to tail and at his heaviest weighed in at 343 pounds. (And we thought OUR babies were rough on the couch!)
Voltaire at 10 months & 200 lbs.-What a HEAD!!