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Bullmastiff Size & Dimensions – How Big Are They?

Bullmastiffs are considered a very large dog breed.

Bullmastiff Size & Dimensions
Weight:50-59 kg (110-130 lbs).
Height:61-68 cm (24-27 inches).
Body Length:61-69 cm (24-27 inches).
Note: Body Length is measured from the base of the tail to the centre of the chest bone & Height is measured from the bottom of the foot to the top of the shoulder (Withers Height)

How Big Are Bullmastiffs Compared to Other Breeds?

In comparison to other breeds, Bullmastiffs tower over small and medium-sized breeds such as Beagles and Bulldogs, both in height and in bulk. They share the very large size category with breeds like Great Danes and Saint Bernards, though they tend to be less tall but more muscular and stocky. Their imposing presence and substantial body mass make them significantly larger and more powerful than large breeds like Labrador Retrievers and German Shepherds, highlighting their distinctiveness as one of the most robust dog breeds in terms of sheer physicality and strength.

How Much Variation in Size Is There Amongst Different Bullmastiffs?

Variation in size among Bullmastiffs can be relatively moderate, with most differences arising from their muscle mass and build rather than their height. Some Bullmastiffs may be leaner and more athletic, while others are bulkier, reflecting variations in breeding and individual health.

To determine if a Bullmastiff is at a healthy weight, their waist should be visible but not exaggerated, and their ribs should be palpable with a slight fat covering, not visible. A side view should show an abdominal tuck. Given their size and propensity for obesity, maintaining a healthy weight is crucial for their overall health and longevity.

When do Bullmastiffs Stop Growing?

Bullmastiffs are considered fully grown at around 18-24 months old. However, they will continue to fill out and develop muscle until they reach about three years old. As puppies, Bullmastiffs can grow very quickly, sometimes gaining as much as 5-10 pounds per week. It is important to monitor their growth and weight to ensure they are developing properly. Overfeeding can lead to obesity and other health problems, so it is important to feed your Bullmastiff a healthy, balanced diet and give them plenty of exercise.

Can You Predict the Size of Bullmastiffs When it is a Puppy?

It is difficult to predict the exact size of a Bullmastiff when they are a puppy. However, you can get a rough estimate by looking at the size of their parents and grandparents. Generally, male puppies will be larger than females, but this isn’t always the case. It is important to choose a reputable breeder who can provide you with information about the health and temperament of their dogs, as well as the size and weight of previous litters.

Essential Items Size Guide for Bullmastiff

ItemSize CategoryMeasurementWhy
CrateVery Large122×76 cm (48×30 inches)Provides ample space for standing, turning, and lying down comfortably, accommodating their size.
BedVery Large120×90 cm (47×35 inches)Offers enough room for a full stretch and rest, supporting their large frame and weight.
KennelVery Large130×100 cm (51×39 inches)Ensures sufficient space for movement and comfort, suitable for their substantial size.
CollarLarge60-70 cm (24-28 inches) in length, 3 cm (1.2 inches) in widthAppropriately fits their large neck, providing comfort and control without being restrictive.

Bullmastiff Size & Dimensions – How Big Are They?