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English Mastiff Growth Chart: Male & Female Weight & Height


Last Updated: July 3, 2023 | 14 min read | 6 Comments

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The giant English Mastiff is an absolutely massive dog. There’s no doubt about it: their size and build are commanding. But have you wondered just what goes into them growing so large?


For one, they have an astonishing growth rate, so they develop in size quickly. Interestingly, they still take longer to reach maturity than a lot of other dogs. As the owner of an English Mastiff, you want to make sure that your dog thrives so it can be as strong as possible. However, you’re bound to ask some questions as your puppy gets bigger.

Some puppies may grow at a quicker rate than others. This is bound to cause some confusion for many pet parents. Sure, you know that they will get huge and bulky, but it’s worth exploring their weight milestones to ensure they’re on track. It’s always good to have points of comparison to ensure your dog is growing up properly. Many factors go into an English Mastiff growth and we will explore them in this article.

Discover what to expect of a full-grown Mastiff, plus get a better idea of how an English Mastiff puppy grows from month-by-month. We also share a chart of your dog’s growth so you have a handy, reliable reference point. Then, we explore the different factors that contribute to your dog’s growth. Lastly, we answer some of the most frequently asked questions about this giant breed’s growth.

What To Expect

Mastiff Puppy
Puppyhood is the most important developmental period of your dog’s life, so it’s important to do it right.

We know that English Mastiffs are going to grow up to be big, strong dogs. However, it also helps to know what to expect. This will help us prepare for all the changes as your puppy grows. While growth charts are helpful, we still need to understand how best to care for our dogs as they fill out their bodies. It’s also good to learn about the many developmental changes that happen during the early years. Before we get into puppy growth averages, let’s take a quick step back to remind ourselves that every dog is different.


This article details the typical growth of an English Mastiff, but your puppy’s path may vary. They may end up having growth spurts or plateaus that overshoot or slow down their growth. This is normal. Your pup may also grow well beyond two years of age. Their overall health also determines their development, so take care to feed them properly and avoid injuries. Ultimately, your puppy may be bigger or smaller than these averages; if you find yourself alarmed by the growth or lack thereof, it is a good idea to consult with a veterinarian to see if your pup is growing up healthily.

Puppy Growth Timeline

Here is a timeline of the average English Mastiff puppy’s growth, plus what to expect of them as they develop. We also cover what you must provide your puppy with during this time.

Young Mastiff
English Mastiffs spend a long time growing up, so it’s wise to monitor their growth closely, to ensure the best health.

Birth To 2 Weeks

There is not much you can do with them from when your puppy is born up to when they are around two weeks old. At this time, they are totally reliant on their mother since they are deaf and blind. It’s a good idea to keep a close eye on mom to make sure she’s eating well, but otherwise, you should let the puppies do their own thing and suckle milk to their hearts’ content. It’s at the two-week mark that the puppies’ eyes will begin to open, and their deafness starts disappearing.

1 Month

At around one-month-old to five weeks old, your puppy’s senses have developed considerably. They begin to be more social with their littermates. At this point, they have at least begun to wean off their mother’s milk. You may start to give them wet food at this point. Ensure they have a lot of time to play with their siblings to help with early socialization.

2 Months

This is the time to separate your puppy from its mom. They should be fully weaned off milk at this point. Obedience training should begin at this stage, as it sets a good foundation for their behavior for the rest of their lives. Housetraining should come easily. They should also be taught not to bite or nip at people and other animals. At this time, we start seeing more normal development happening.

Here is what you can expect from male and female English Mastiffs. We will continue this observation through the rest of this section.

  • Males: weigh an average of 29 pounds and stand around 13.5 inches.
  • Females: weigh an average of 24 pounds and stand around 12 inches.

3 Months

At three months old, your English Mastiff puppy’s training and socialization continue. It would be a good idea to start leash training at this time to get them used to the feel of the leash and harness. Take care not to take them out for long walks just yet, as overexertion can be very difficult for your puppy. Walking long distances on hard surfaces can also disrupt proper bone development. Continue to expose your dog to new people, animals, places, and situations to make for a well-rounded dog in the future.

  • Males: weigh an average of 45 pounds and stand around 15.5 inches.
  • Females: weigh an average of 39 pounds and stand around 13.3 inches.

4 Months

At around the four-month mark, your puppy should be happily settled in to its new home. Continue obedience training and socialization as usual. You may both benefit from classes to help with training. Puppy kindergarten classes are also a good idea to help your dog understand how best to behave around other dogs. This will help them grow into confident, non-aggressive adults. Be sure they aren’t exercising heavily at this point in their life, as this could injure them.

  • Males: weigh an average of 60 pounds and stand around 18 inches.
  • Females: weigh an average of 50 pounds and stand around 17 inches.

5 Months

By the time your Mastiff puppy has reached five months old, you may be astonished at how fast they are growing! They may start becoming harder to handle as they grow, learn, and play. We encourage you to be patient with them and reward good behavior. Positive reinforcement can make all the difference in their training. You can continue behavior training classes as necessary. Begin introducing more playtime at this age, though we still recommend only exercising your dog for short periods at this age.

  • Males: weigh an average of 80 pounds and stand around 20 inches.
  • Females: weigh an average of 65 pounds and stand around 18 inches. This is the age they begin to be noticeably smaller than male dogs.

6 Months

When your dog has reached six months old, they are really starting to fill out their bodies well. Start routines with your puppy to give them a sense of structure. Being a firm, confident leader at this point in their lives will help them to see you as their authority figure. They may be rambunctious, but you should still treat them with patience. Be sure to curb bad behavior as you see it, but always encourage good habits as well.

  • Males: weigh an average of 100 pounds and stand around 21.5 inches.
  • Females: weigh an average of 80 pounds and stand around 19 inches.

7 Months

When your puppy is at seven months of age, they should be well set in their day-to-day life with you. Your routines should be well-fleshed out and followed daily. It’s normal for them to act out from time to time, but you should still stand firm with them to discourage bad behavior. At this point, they should be well-adjusted to the people and animals who share their home. Socialization should continue with new people to help them conquer any fears.

  • Males: weigh an average of 125 pounds and stand around 22.5 inches.
  • Females: weigh an average of 90 pounds and stand around 20 inches.

8 Months

When month eight comes around, you may notice that your English Mastiff has bonded to you quite well. Because of this, they may start developing separation anxiety if left alone for too long. This can lead to destructive behavior. When possible, it is best to leave someone to watch your dog so they don’t get bored and lonely. Beyond separation anxiety, your dog should be maturing at a satisfactory pace. They should be eating, exercising, and socializing on a proper schedule.

  • Males: weigh an average of 140 pounds and stand around 23.3 inches.
  • Females: weigh an average of 100 pounds and stand around 20.5 inches.

9 Months

You can expect your dog to start maturing more rapidly at around the nine-month mark. They will still be very playful, but should behave relatively well if their needs are met. Just bear in mind that they can be very destructive when they get frustrated, so ensure that they’re always cared for. Toys are a great way to keep them mentally and physically stimulated, so be sure to provide them with plenty.

  • Males: weigh an average of 155 pounds and stand around 24.5 inches.
  • Females: weigh an average of 110 pounds and stand around 21.3 inches.

10 Months

At ten months, you will see your dog’s growth slow. This is normal and part of the development process. You can still expect boundless energy, but again, they will be more inclined to listen to you now that you have established trust and a good rapport.

This is around the age when you will be able to take them for longer walks, though you shouldn’t give them more than they can handle. Two 25 minutes walks per day will make all the difference in helping them expend their energy.

  • Males: weigh an average of 165 pounds and stand around 25 inches.
  • Females: weigh an average of 115 pounds and stand around 21.5 inches. This is where females often hit a growth plateau.

11 Months

Your dog should be adjusted to home life very well by the time they are eleven months old. They will be an established member of your family and should act as such. They start mellowing out and becoming more relaxed, though they still require an hour’s walk split into two sessions daily. They also benefit from playing games with you in the yard or at the dog park. But be sure not to do anything too strenuous so they don’t accidentally get hurt.

  • Males: weigh an average of 170 pounds and stand around 25.5 inches.
  • Females: weigh an average of 115 pounds and stand around 21.7 inches.

1 Year

At this point, now that your dog has reached their first birthday, home life should be harmonious. It may be difficult to rein them in sometimes given their size, but that’s why early obedience training is essential– just imagine if you hadn’t done it! Continue to support their growth with proper nutrition and care to help them grow into their adult body. Your Mastiff still has quite a bit of growing to do, even well past the one-year mark!

  • Males: weigh an average of 175 pounds and stand around 26 inches.
  • Females: weigh an average of 120 pounds and stand around 22.5 inches.

What Happens Next?

Dog in Water
Mastiffs are very unique dogs in that it takes a long time for them to reach full bodily maturity.

They can still grow even when they have reached five years old. Thus, after a year has passed, it is entirely normal for your dog to keep growing. It’s a good idea to keep tabs on their growth as they age. You can compare notes with your veterinarian to see if your dog is on track. However, what really matters is their overall health. If your dog is healthy, then there is no reason to worry about how big they are.

Full-Grown English Mastiff

Your gorgeous, affectionate, calm Mastiff will have grown a lot over five years. You can expect them to be truly massive both in weight and height– but also in heart. These dogs are very sweet and love nothing more than to be by your side.

With regard to numbers, there’s a lot to consider. A Male English Mastiff’s average weight ranges between 160 and 230 pounds. Females are much smaller, weighing 120 to 170 pounds on average. As for height, it’s a bit trickier. AKC standard doesn’t give a specific maximum height for full-grown Mastiffs. However, males stand a minimum of 30 inches, while female breed height standards start at 27.5 inches tall.

Growth Charts

We’ve put together two growth charts for the English Mastiff– one to track weight and one for height. This provides a quick and handy reference point when considering your dog’s growth. Just remember that the numbers we give are averages; your dog may fall outside these standards.


AgeMale Weight (lbs.)Female Weight (lbs.)
2 months2924
3 months4539
4 months6050
5 months8065
6 months10080
7 months12590
8 months140100
9 months155110
10 months165112
11 months170115
12 months175120
14 months185125
16 months189126
18 months192129
2 years205135
3 years220150
4 years225160
5 years230170

As you can see, many of these dogs grow to be heavier than many humans are– which can make them much more than a handful! Obedience training is important to critical to ensure they don’t topple anyone over by jumping up on them whenever they’re excited.


AgeMale Weight (lbs.)Female Weight (lbs.)
2 months13.512
3 months15.513.3
4 months1817
5 months2018
6 months21.519
7 months22.520
8 months23.320.5
9 months24.521.3
10 months2521.5
11 months25.521.7
1 year2622.5
Full grown3027.5

This chart is shorter than the weight one because the AKC doesn’t have a standard for maximum growth of an English Mastiff. Once fully grown, males should be around 30 inches tall and 27.5 inches tall for females. However, many dogs fall outside these numbers.

Factors To Consider

Panting dog
Mastiffs spend a long time growing up, so it’s wise to monitor their growth closely, to ensure the best health.

It’s important to consider these factors to ensure that your dog grows up properly. These will also help you understand factors that affect your pup’s growth, allowing you to rest easy, even if it’s not going the way you imagined.


English Mastiffs are bred to be giant dogs. This is part of their genetic line, but some dogs are larger than others. While you can usually get a good picture of how large your dog will be by looking at the parents, you can’t always guarantee that size will manifest. This is just a small part of the overall genetic picture.

Parents may have genes that indicate their offspring will be smaller, the same size, or larger than they are, and there is no way to tell until your dog has gotten to that point. You might ask your breeder about previous offspring lines to see what kind of puppies the parents have produced.


Nutrition is the foundation of your dog’s good health and can be a determining factor in how large or small your dog will grow. It’s a common misconception that overfeeding will lead to the largest dog possible. In reality, this just paves the way towards obesity, which can cause a myriad of preventable diseases.

In the first two formative months, ensure that your dog is getting enough milk from its mother. It’s important to feed your dog a few appropriately-sized meals daily of the best dog food for Mastiffs, ensuring balanced health and nutrition. The food should be designed for large or giant breed dogs, providing the complete, balanced nutrients necessary for growing bodies. Giving them vitamins and minerals can also help to ensure growth.

Growth Spurts & Plateaus

Growth spurts and plateaus can happen to any developing dog at any age. Sometimes, you may encounter plateaus at certain times in your dog’s life. For example, female English Mastiffs often reach a plateau around ten months. While you cannot count on growth spurts or plateaus to happen exactly when you expect them, it’s important to realize that your dog is doing their best to grow at its own pace. Growth spurts are random, so don’t stress about them too much. Simply do your best to care for your dog, and their bodies will take care of the rest.

Neutering & Spaying

Spaying or neutering your dog early in life will not stunt its growth. However, as a large breed dog, your English Mastiff’s joints may be affected. Some studies show that early spaying or neutering can affect a dog’s growth plate. This could delay its closure and allow dogs to grow taller than they usually would. While this may sound good, this may predispose them to joint disease later in life.

Be sure to ask your veterinarian when it is appropriate to spay or neuter your dog. As a rule of thumb, females should be fixed after their first heat cycle, while males should be altered around two years old.

Physical Health

The final factor to consider is your dog’s overall physical health. If your pup is unwell for a long time, this may stunt its growth. Poor health doesn’t allow the body to reach its full potential, so take your sick dog to the veterinarian to ensure everything is alright.

Overexertion is another factor to avoid, as it can injure your dog. Take care not to over-exercise your English Mastiff.

Lastly, given their vast size, it is vital to allow lots of space for your Mastiff to play. This helps prevent injury and allows their muscles to develop through full and free movement.

Frequently Asked Questions

Dog looking at camera
Watching your dog grow can cause some form of anxiety — this is normal for a loving pet parent. 

Let’s answer some of the most frequently asked questions from English Mastiff owners who just want the best for their dogs.

When will my English Mastiff stop growing?

This giant breed grows at a fast pace; many of them double in size within three months! However, they will reach full maturity slowly– somewhere around two years old. Despite this, they will continue growing even after they are four years old!

Your dog’s growth rate will stabilize at the two-year mark, so they will not be growing up anywhere near as quickly as they did in puppyhood. However, you can still expect them to gain pounds and inches, albeit not as noticeably as before. Growth stops around 5 years of age, at which point they will be perfectly massive.

How fast can my Mastiff grow?

English Mastiffs grow at an astonishing rate. However, there’s no real way to peg this rate for your dog, as they are susceptible to random growth spurts and plateaus.

Like when we discussed genetics, you can look at your dog’s parents and relatives to have a rough indication of how large they might grow. However, your results will likely vary. Some dogs may start out small but suddenly shoot up in weight and height later in life. Some other dogs will start larger than their littermates but then slow in growth after hitting a plateau.

There can be a lot of size discrepancy among giant size breeds, English Mastiffs included.

Will my puppy experience growing pains?

Studies show that puppies do not really experience growing pains. However, certain orthopedic conditions may give them pain. Suppose you notice limping, swelling, an unusual gait, or a hesitance to be involved in previously enjoyable activities. In that case, it’s worth bringing your dog to the vet to get a closer look at what’s going on.

Letting your dog play too roughly or exercise too much can lead to injury, which can also bring them pain. Take care to give your dog ample space to play, and do not let them overexert themselves. These measures will minimize the chance of injuries.

What are some conditions common to Mastiffs?

The most common conditions that affect growing English Mastiffs are orthopedic. Since they are a giant breed, Mastiffs may experience hypertrophic osteodystrophy as they grow up. This condition introduces painful swelling in the growth plates, often accompanied by a fever. This issue resolves itself on its own most of the time.

Another condition commonly seen in growing Mastiffs is hip dysplasia, where the thigh bone does not fit properly in the hip socket. This is very painful and can progress to arthritis, so surgery is recommended to repair the issue. Thankfully, most reputable breeders screen for hip dysplasia and do not allow parents with this condition to breed.

What if my English Mastiff isn’t the correct weight?

If your English Mastiff is not the correct weight, there are a few ways to assess the best course of action. A Mastiff’s weight is going to depend on how large they have become size-wise. You should expect them to get chunkier as they grow older. A good test to see if your dog is overweight or underweight is by checking their ribs. By lightly pressing on your dog’s ribs, you should be able to feel them, though you should not be able to see them.

Too much fat will require a balanced diet, plus extra exercise. Too little fat will require veterinary assistance. An underweight dog may need deworming for internal parasites. Ultimately, it’s always a good idea to ask your veterinarian to help determine solutions for overweight or underweight dogs.

Final Thoughts

English Mastiffs are huge and bulky dogs who have a lot of growing up to do. As they age, you must attend to their needs because they are looking to you to provide them with the best care possible.

We hope you have gained a better understanding of your Mastiff’s growth patterns. Countless factors go into your dog’s growth, but we applaud you for taking the time to research so you know what to expect. This way, you can be assured that you are giving your dog the best care.

Be sure to bring your dog in for regular veterinary checkups. This way, you can clearly see if your dog is on track for its best growth potential.

Close Up of Senior Dogs

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