Bullmastiff Weight Chart – Size & Growth Chart

Bullmastiff Weight Chart

The adult size of a Bullmastiff is an important consideration before introducing one into your home. A Bullmastiff weight chart will give you an idea of how big he is going to grow.

So, you can decide whether your current residence is big enough for him. The Bullmastiff is a large dog that needs a lot of room to move about.

The history of this large-breed dog breed is fascinating. The Bullmastiff became known as “The Gamekeeper’s Night Dog” in 19th-century England when they were developed specifically to protect the aristocracy’s vast rural estates from poachers.

The Bullmastiff is the offspring of a Mastiff and a Bulldog, with 40% Bulldog and 60% Mastiff genetics.

This new breed was developed to help the estate owner get his just retribution in court by capturing and detaining a poacher without harming the trespasser.

In this article, we will share with you a Bullmastiff growth chart that should give you a decent idea of how fast a Bullmastiff puppy will mature into an adult dog as well as a host of other relevant information.

When Do Bullmastiffs Stop Growing?

Bullmastiff Puppy Size

The Bullmastiff, like other large dog breeds, takes its sweet time growing up.

The only information we have on how fast these pups mature is anecdotal, based on the experiences of individual breeders and dog owners, since no formal studies have been undertaken.

Like humans, dogs all develop at various rates. Dog owners have found that their pets’ growth slows or stops at around 18 and 20 months of age, however, certain breeds continue to add weight up to the age of two.

After the age of two, a Bullmastiff may continue to acquire weight and get plumper without increasing in height.

Bullmastiff Growth Chart

Remember that the averages on the Bullmastiff weight table below are just that, and that your dog may be somewhat larger or smaller than the listed weights.

Dogs, like people, are unique and develop at their own pace.

These pups develop rapidly. Males double their weight at the end of the second month, with females closely following.

In fact, by the third month, both the females and males will have almost doubled their initial weight.

This phenomenally rapid development rate moderates at the sixth-month mark, but both sexes continue to add at least 4 to 5 pounds every month.

To get the best from the Bullmastiff weight chart below, you need to have an accurate record of your dog’s age and match it with the closest corresponding age on the left column of the chart. Then follow the same row for the weight of your Bullmastiff.

Bullmastiff Weight Chart

Age Male Weight lbs Female Weight lbsMale Weight kg Female Weight kg
3 Months 37 - 43 lbs34.5 - 40 lbs16.5 - 19.5 kg15.5 - 18 kg
4 Months48 - 55 lbs44 - 52 lbs21.5 - 25 kg20 - 23.5 kg
5 Months58 - 66 lbs54 - 62 lbs26 - 30 kg24.5 - 28 kg
6 Months69.5 - 77 lbs64 - 74 lbs31.5 - 35 kg29 - 33.5 kg
7 Months74 - 85.5 lbs68 - 82 lbs33.5 - 39 kg31 - 37 kg
8 Months82 - 93.5 lbs75 - 88 lbs37 - 42 kg34 - 40 kg
9 Months89 - 98.5 lbs80 - 92 lbs40 - 44.5 kg36 - 42 kg
10 Months92 - 105 lbs84 - 99 lbs42 - 47.5 kg38 - 45 kg
1 Year102 - 118 lbs93 - 110 lbs46 - 53.5 kg42 - 50 kg
2 Years110 - 130 lbs100 - 120 lbs50 - 59 kg45 - 54 kg

Bullmastiff Puppy Development Stages

Bullmastiff Development

Birth – 2 Weeks

In the first two hours of its life, a Bullmastiff puppy has to be fed every two hours.

Given the high metabolic rate of this breed’s puppies and their propensity for producing big litters, supplementing the mother’s milk with that from a bottle may be essential.

The mother dog licks her pups to stimulate elimination at this time. If she doesn’t, the dog’s owner will have to pitch in, which isn’t a bad thing since early socialization is crucial for this breed.

3 Weeks – 12 Weeks

The mom will regurgitate its chow at this time for the pups.

Puppies at this stage are ready to be fed high-quality puppy kibble diluted with water. Keep a dish of water ready for the pups to drink now as well.

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Puppies may start eating adult food once they reach 12 weeks of age.

Ensure that the transition is smooth by making sure the food is not too tough for their mouths. As a preventative measure against bloat, the pups should be given food twice daily.

4 Months – 9 Months

You should begin cleaning your dog’s teeth twice or thrice weekly starting when he or she is four months old.

You may begin taking your dog on regular 30-minute walks once he or she reaches the age of five months.

These dogs don’t need strenuous physical activity at this time, but it is still important to keep them intellectually engaged with games like fetch and chew toys.

Bullmastiff Size Chart

Bullmastiffs are large, powerful dogs with a rapid growth rate. It’s important to keep your dog from becoming overweight or too active, both of which may lead to health problems.

Do not let your Bullmastiff leap over barriers or off of furniture until he is at least a year old.

At 9 months old, your Bullmastiff may begin socialization. Do this by bringing him along on errands and exposing him to new sights, noises, and people.

10 Months – 18 Months

Your Bullmastiff will keep growing but at a very slow rate.

Up until the age of 18 months, your dog’s muscles, bones, and joints will still be developing, so it’s crucial that you take extra care to avoid over-exerting him.

Bullmastiffs don’t have the stamina for long hikes. Your dog would benefit more from short, daily walks of 15 to 20 minutes than from lengthy, strenuous treks.


Large and intimidating, an adult Bullmastiff may scare away any would-be attackers.

The Bullmastiff relies on his massive size and intimidating appearance to scare away unwanted visitors rather than his barking.

These canines are low-energy and OK with a few short walks each day. Because of this, Bullmastiffs do well in urban settings.

They are easygoing dogs who are content to spend time alone as they value quality time with their families when they are together.

How Big Do Bullmastiffs Get?

Bullmastiffs range in size considerably since their stature is determined by that of their parents.

It’s more probable that a pup will be a huge size if both of its parents are large.

Bullmastiff Growth Chart

Using the weight chart in this article might help you predict how large your Bullmastiff will grow to be.

The tables provide you a ballpark figure for how much your Bullmastiff puppy might potentially weigh at various years, given its breed and sex.

The size of a Bullmastiff may also be estimated by looking at the dog’s paws. As a dog has big paws, it’s usually a sign that it’ll be a big dog when it grows up.

Finally, a DNA test may provide more accurate details on the size and other physical traits of a Bullmastiff.

These checks examine the dog’s genes to provide you with an in-depth picture of its breed, size, and other characteristics.

A Bullmastiff’s size might vary widely, but you can obtain a good approximation by following these guidelines.

Bullmastiff Size Chart

When Bullmastiffs reach physical maturity, they may grow to be massive. Studies only reveal average growth data for all Bullmastiffs, but yours might be different.

That means, your Bullmastiff may weigh more than the weight shown in our Bullmastiff size chart above, and he or she may also grow taller. Similarly, it could be shorter than average.

Male Bullmastiffs may weigh between 110 and 130 pounds and stand 25 to 27 inches tall when fully grown.

A female Bullmastiff weighs between 100 and 120 pounds and is between 24 and 26 inches tall.

Height is harder to measure than weight. To get the right height, you’ll need additional knowledge.

Start with a carpenter’s level, measuring tape, pencil, and doorway or wall.  Dog height isn’t measured from paws to head. From paws to withers is the correct measurement.

First, have your Bullmastiff stand against a wall. You can’t make it stand straight. Bullmastiffs aren’t hairy, so finding their withers ought to be easy. The carpenter’s level should be set where the withers meet the neck.

Place the level across your Bullmastiff’s withers so it strikes the wall. For precise measurements, keep your hands firm and the level straight.

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Then, mark the place the level touches the wall. Your Bullmastiff’s height is now on the wall.

All that’s left is to get a number. Measuring tape from ground to wall mark. Your Bullmastiff’s height is on the tape.

Will Neutering/Spaying My Bullmastiff Affect His Growth?

There are various myths concerning how spaying or neutering dogs prior to puberty might lead to slower development.

In reality, undergoing these procedures produces an increase in height, which may lead to a plethora of problems in the future.

Of course, there are several advantages to spaying/neutering Bullmastiffs while they are young, but the risks are significantly larger.

Spaying your female Bullmastiff should be done after her first heat cycle. Males shouldn’t be neutered before they have reached the age of two.

The reason for this is simple and clear: Bullmastiffs do not grow as quickly as other breeds, which need 9 to 18 months.

They are still growing even into the second year of their lives (third year in some cases). The ovaries and testes produce hormones that regulate bone development and shape as they age.

Since Bullmastiffs are still developing in the second year of their life, spaying or neutering them too soon can result in difficulties.

Early “fixing” causes a delay in the closure of the growth plates, prompting the dog to grow bigger and perhaps creating health concerns in the long run.

Mastiff Vs Bullmastiff Size

Mastiffs and bullmastiffs are enormous dog breeds, however their sizes differ.

Mastiffs weigh between 150 and 250 pounds and 120 to 190 pounds, respectively. Males stand at least 30 inches tall and females at least 27.5 inches.

Bullmastiffs weigh between 110 and 130 pounds and 100 to 120 pounds, respectively. Males stand 27 inches at the shoulder and females 25 inches.

Both breeds are powerful, muscular, and huge. Both are robust, athletic canines well-suited for protection, guarding, and family companions.

Individual dogs within a breed might vary greatly in size, so it’s crucial to see a dog in person to learn about its behavior and features before deciding whether it’s perfect for you.

Factors That Affect Bullmastiff Growth 

Bullmastiff Puppy Growth Chart

Genetics & Gender

A Bullmastiff’s size of is determined by genetics. The birth parents’ size will give you a decent idea of the eventual size of their kids.

This indicates that tiny dogs will most likely produce smaller children, whereas larger dogs will always have larger offspring. When it comes to gender, females are usually smaller than males.


A Bullmastiff should not grow too rapidly since this might lead to physical development issues.

A puppy that is fed puppy chow for an extended period of time will develop too quickly. You should only provide puppy food to him until he is a year old.

It is preferable to give your puppy big-breed puppy food. This diet provides all the nutrition he needs without allowing him to develop too quickly.

Physical Activity & Health

Bullmastiffs are low-energy canines that do not need a lot of rigorous activity to be healthy.

Walking is the greatest exercise for this breed, and it should be done once or twice a day for roughly 15 to 30 minutes.

You may also experiment with food puzzles and agility toys. Bullmastiffs also like to play fetch and Frisbee.

However, don’t overdo it with exercise while your dog is young. He may be enormous at one year old, nevertheless, he is still a pup and shouldn’t be overworked.

How Much To Feed A Growing Bullmastiff Puppy?

You may use the feeding instructions supplied by the food manufacturer to decide how much to feed a Bullmastiff puppy.

Typically, these recommendations will propose a daily feeding quantity depending on the puppy’s weight and age.

Bullmastiff Puppy Development

It’s critical to follow these guidelines and avoid overfeeding the puppy, since extra weight may put undue pressure on a growing Bullmastiff’s developing joints.

Typically, these recommendations will propose a daily feeding quantity depending on the puppy’s weight and age.

A 10-week-old Bullmastiff puppy weighing 20 pounds, for example, may need around 2 1/2 cups of food per day, but a 16-week-old puppy weighing 40 pounds may require about 4 1/2 cups per day.

To assist support the puppy’s developing physique, split the daily feeding quantity into two or three smaller meals.

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How To Tell If Your Bullmastiff Is Underweight Or Overweight? 

It’s easy to see whether your Bullmastiff is too heavy or too thin.

Knowing whether your Bullmastiff’s weight fluctuates into an unhealthy zone may be relatively straightforward if you maintain a consistent record of its weight.

However, weight isn’t always the best indicator of whether or not your dog has gained too much or lost too much weight.

When observing your Bullmastiff closely, you may detect whether he or she is too heavy or too thin. There are telltale indicators on its ribs, waist, and hips.

When you examine your dog and notice excessive amounts of bone, this is an indication that he needs to gain some weight.

However, visuals alone aren’t enough to do it right. You will need to use your fingertips to touch your Bullmastiff’s body. Your dog may be overweight if the bones in his or her joints are not perceptible.

Do Bullmastiffs Experience Growing Pain?

Large breed dogs, like Bullmastiffs, often go through a period of “growing pains” during their formative years.

As a dog grows, it may experience some discomfort as its bones and muscles readjust to the new demands placed on them.

In the first year of their lives, Bullmastiffs, like many other large-breed dogs, tend to develop quickly. Some discomfort in the legs and joints is common as a result of this fast development.

Bullmastiffs may show signs of discomfort during growth such as stiffness, limping, and trouble getting about.

Talk to your vet if you think your Bullmastiff could be suffering growing pains. If your dog is in discomfort, a trip to the vet can help pinpoint the problem.

Most occurrences of growing pains are short-lived and treatable with bed rest, little activity, and maybe some pain medication.

What To Do If My Bullmastiff Is Not The Right Weight?

Health conditions, food, or activity levels may affect your dog’s weight. If your dog is underweight or overweight, see a vet.

If you suspect your dog’s diet, take action. Giving your dog biscuits as a reward adds needless calories to their diet.

Feed your dog high-quality food. Feed your dog 25% protein adult kibble. High-protein puppy food may contribute to hip dysplasia.

Also, exercise your dog. High-calorie food and lack of exercise will make your dog fat.

How To Properly Weight My Bullmastiff?

Puppies should be weighed often to ensure they are growing at a healthy rate and are not becoming overweight.

If you want to know how much your Bullmastiff weighs, you’ll need a bathroom scale. Get started right away by taking your weight on the scale. Take your new dog with you and go onto the scale.

Bullmastiff Puppy Diet

Finally, subtract your own body mass from that of you and your Bullmastiff. Your pet weighs the resulting amount.  You can also get a dog scale if your Bullmastiff is calm enough to sit on it.

Bullmastiff Genetics And Common Health Problems

Elbow and Hip dysplasia are the most frequent health complications for Bullmastiffs. Research has shown that 25.4% of dogs in this breed are dysplastic in at least one of their hips or elbows.

Dogs with this ailment are unable to walk normally because their joints are malformed. As a result, the damaged joint may develop painful arthritis.

Injury to the cruciate ligament and Wobbler’s syndrome are only two examples of the orthopedic disorders that affect Bullmastiffs.

Many of these canine companions succumb to cancer. Sadly, lymphoma is rather frequent.

Cherry eye, retinal dysplasia, glaucoma, progressive retinal atrophy, and persistent pupillary membranes are just a few examples of the many eye problems that plague Bullmastiffs.

The average lifespan of the breed is low. Bullmastiffs typically live between 8 and 10 years, while some may live much longer. There have been reports of Bullmastiffs living to be 11 years old.

Final Words

Generally calm and sociable among family, Bullmastiffs might be wary of other dogs and strangers.

Despite their large size and threatening appearance, they are kind to infants and young children. Mastiffs have a sedentary lifestyle that includes plenty of couch time.

They may require up to 3 years to fully grow, during which time you may be burdened with a very large and hefty dog demanding constant attention and a place on your lap.

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