Skip to content

Bullmastiff puppy growth: milestones and weight estimates

How fast a Bullmastiff puppy grows, illustrative weight estimates and the limits of predicting adult size.

Bullmastiff puppies grow at a startling rate, often gaining 1.5 to 2.5 kg a week at their peak and reaching around 30 to 40 kg by six months. Height comes first, usually by 12 to 15 months, while the chest, head and muscle keep developing until roughly 2.5 to 3 years.

A Bullmastiff puppy needs an exercise plan matched to its individual development, not an age multiplied by five minutes. Avoid forced running and repetitive high-impact activity while growing, and ask your vet about suitable movement, feeding and body condition. Pain, limping or difficulty getting up needs veterinary attention rather than a harder fitness routine.

Bullmastiff puppy growth in numbers

0.0153045602m4m6m8m10m12m14m16m18m21m24mkg

Illustrative size-based model for a male Bullmastiff, in kg, by age in months

AgeFemaleMale
2 months4.4 kg4.8 kg
3 months7.2 kg8 kg
4 months11 kg12 kg
5 months15 kg16.5 kg
6 months18.5 kg20.5 kg
7 months21.5 kg24 kg
8 months24.5 kg27 kg
9 months27.5 kg30 kg
10 months30 kg33 kg
12 months34.5 kg38 kg
14 months38.5 kg42 kg
16 months41.5 kg45.5 kg
18 months43.5 kg48 kg
21 months46.5 kg51 kg
24 months48 kg53 kg
30 months49.5 kg54.5 kg

This is an editorial model scaled to a typical adult weight, not an observed breed average, a validated growth standard or a healthy-weight range. Do not adjust food to make a puppy follow this line. Discuss actual growth measurements with your vet.

Puppy growth guides for similar-sized breeds