🐕‍🦺 X-Large · United Kingdom (England)

Mastiff: Size, Weight & Temperament

A giant, calm molosser breed with an enormous body weight that, despite modest exercise needs, requires experienced, consistent handling from puppyhood.

! Experienced only
Mastiff dog breed portrait
Photo: Joachim Otto · CC BY-SA 3.0 · Wikimedia Commons
Weight male72–104 kg
Weight female54–77 kg
Shoulder height70–90 cm
Size classX-Large (over 45 kg)
Fully grownat approx. 24 months
Life expectancy6–10 years
Activity levelLow
OriginUnited Kingdom (England)
ClassificationFCI Group 2 (Pinscher and Schnauzer, Molossoid and Swiss Mountain and Cattle Dogs)
Temperament & character

The Mastiff is calm, good-natured, and rarely aggressive toward its own family, though its sheer size and presence can appear intimidating to strangers. It is generally deliberate and not very impulsive.

Exercise & stimulation

Despite its bulk, the Mastiff needs only moderate, joint-friendly exercise; long walks and jumping should especially be avoided during growth. As an adult, calm, regular walks are sufficient.

Grooming

The short coat is low-maintenance, but the skin folds on the head and lips must be cleaned regularly to prevent infections. The breed tends to drool heavily.

Suitable for beginners?

Its enormous body weight and size require consistent, experienced leadership from puppyhood, since a grown Mastiff is nearly impossible to control physically without proper training. The breed is generally not suited to first-time owners.

Health & common problems

As a giant breed, the Mastiff is especially prone to hip and elbow dysplasia (HD/ED), gastric dilatation-volvulus (bloat) due to its deep chest, and heart conditions such as dilated cardiomyopathy (DCM). Its short life expectancy is typical for giant breeds.

Good with: Experienced owners with space and giant-breed experience

Is your Mastiff at a healthy weight? Calculate the ideal weight and the right portion size for free in the Souldog app.

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This information is for general guidance and does not replace veterinary or breeder advice. Temperament and health vary individually within every breed.