Because weight is such a big topic with Mastiffs, I decided to write a little about what I have experienced over the last 20 years.  Mastiff growth is not “one size fits all”.  My 200+ pound female, Rita, was only 10 pounds at 8 weeks old and started out as one of the smallest puppies in the litter.  At the time I was worried because she wasn’t as big as the “charts” said she should be.  But since she was the only apricot female, and I wanted to keep an apricot like her mother, I went ahead and kept her.  By the time she was 3 she weighed over 200 pounds.  On the other hand, Doc was over 55 pounds at 11 weeks and over 200 pounds by 18 months.  Doc grew faster and Rita was a slow steady grower, but as adults they are both excellent examples of the breed. 

Some people insist on force feeding their puppy huge quantities of food in at attempt

to put on weight at a faster rate.  I can’t emphasize enough not to fall into this trap. 

Since all Mastiffs mature at different rates, forcing them to gain weight in order to fit into a weight chart

at a specific time would be detrimental to their development.

I would personally prefer a slow, steady rate of growth as opposed to a rapid weight gain. 

This allows the puppy’s joints and bones to develop before so much additional weight is added to their frame.  Of course some dogs, like Doc, are going to be heavier at an early age and you can’t do anything about that.  You just need to make sure they are not overactive during their growth period,

putting more stress on their joints.

I was reluctant to publish the weight chart that so many people go by,

but I decided to include it in addition to actual Mastiff puppies and their true weights from owners 

in the Mastiff  community.

10WKS 12LBS MISSY APRICOT FEMALE

10WKS 13LBS GRETA FAWN FEMALE

10WKS 16LBS ATILLA BRINDLE MALE

10WKS 18LBS SANDY FAWN FEMALE

10 WKS 20LBS BRUTUS BRINDLE

10WKS 22LBS MOJO BRINDLE MALE

10WKS 25LBS BARON APRICOT MALE

10WKS 26LBS DIESEL BRINDLE MALE

10WKS 29LBS KODA FAWN MALE

10WKS 29LBS DIESEL FAWN MALE

10WKS 31LBS ARCHIE FAWN MALE

10WKS 32LBS HERMES MALE

11 WKS 24LBS MAJOR

11WKS 29LBS AUDS BABY

11WKS 30LBS OTTO FAWN MALE

11WKS 32.8LBS BUSTER BRINDLE MALE

11WKS 34.8LBS DAISY FEMALE

11WKS 41LBS SAJAK FAWN MALE

11WKS 44LBS DARWIN FAWN MALE

11.5 WKS 24LBS SIMON MALE

11.6WKS 36.2LBS KENAI

3MO 17.25 LBS ADA BRINDLE MALE

3MO 19LBS CUJO FAWN MALE

3MO 25LBS BUDDY MALE FAWN

3MO 27LBS ATTICUS FEMALE

3MO 27.5LBS ZEUS FAWN MALE

12WKS 28LBS HERCULEEZ FAWN MALE

3MO 29LBS KALYPSA FEMALE

12WKS 32LBS KOLLOW BRINDLE FEMALE

3MO 32.6LBS BELLE FAWN FEMALE

12WKS 35LBS MUNCHKIN FAWN FEMALE

12WKS 36LBS CASSIE FEMALE

12WKS 37LBS DIESEL FAWN MALE

12WKS 38LBS KODA FAWN MALE

12WKS 39LBS HERMES MALE

3MO 40LBS SIMON FAWN MALE

3MO 41.1LBS BUSTER BRINDLE MALE

3MO 47LBS ROZI APRICOT FEMALE

As you can see above from actual Mastiff puppies, there a huge range of weights. 

At 10 wks alone the weight range is 12# to 32#.

Here is another chart below.  The averages above indicate the chart below is more on the “high average” side. 

The main thing is that your puppy be healthy and happy. 

The chart is monthly, and has puppies gaining as much as 25 pounds in one month,

and then only 7 pound in 6 months for females from 1 year to 18 months. 

Your puppy might not gain 25 pounds in one month, as in the 6-7 month projection in the chart below,

but she might gain more weight than the chart predicts from 1 year to 18 months...

During this time the charts projects a female gain just 7 pounds. 

Rather than gaining 7 pounds during that period, Rita gained over 30 pounds. 

             AGE                                        MALE/FEMALE

8 WKS                                           29/24

9 WKS                                           32/29

10 WKS                                          36/32

11 WKS                                          40/36

3 MO                                             45/39

4 MO                                             60/50

5 MO                                              80/65

6 MO                                            100/80

7 MO                                             125/90

8 MO                                           140/100

9 MO                                            155/110

10 MO                                           165/112

11 MO                                           170/115

1 YR                                             175/120

13 MO                                           180/122

14 MO                                           185/125

15 MO                                            188/125

16 MO                                           189/125

17 MO                                            190/127

18 MO                                            192/127

2 YRS                                            205/140                        

30 MO                                            210/135

3 YRS                               215-225/155-180

4 YRS                               220-230/160-190

5 YRS                               220-235/170-200

Here is another popular weight chart.  I tend to prefer this one because it isn’t

broken down by weeks, so owners don’t panic if their puppy is above or below a

specific # on a specific day.  It also gives a range of weights. 

Each chart ends up at the same weight at maturity, but it’s not a race to get there. 

There is a wide range because they don’t differentiate between male and females....males being heavier.

There can also be a large variation of weights at 6-8 weeks if a litter was very large,

there were any problems with the mother nursing (mastitis, infection, low milk production)

or puppies who had to be bottle fed for one reason or another.

By 3 months or so, these puppies usually have caught up with the averages.

8 Weeks: 15-25 lbs

6 Months: 65-85 lbs

1 Year: 110-170 lbs

18 Months: 140-185

2 Years: 160-200

3 Years: 170-220