Spanish Mastiff weight by age
Typical weight by age for a Spanish Mastiff with an adult weight of about 170 lb (male) or 170 lb (female). The range shows where most puppies fall.
| Age | Male | Female |
|---|---|---|
| 2 months | 27 lbrange 18–36 lb | 27 lbrange 18–36 lb |
| 3 months | 45 lbrange 33–59 lb | 45 lbrange 33–59 lb |
| 4 months | 67 lbrange 51–83 lb | 67 lbrange 51–83 lb |
| 5 months | 91 lbrange 73–110 lb | 91 lbrange 73–110 lb |
| 6 months | 108 lbrange 87–128 lb | 108 lbrange 87–128 lb |
| 8 months | 134 lbrange 113–154 lb | 134 lbrange 113–154 lb |
| 10 months | 147 lbrange 124–165 lb | 147 lbrange 124–165 lb |
| 12 months | 155 lbrange 134–171 lb | 155 lbrange 134–171 lb |
Divide pounds by 2.2 for kilograms.
Adult weight
AKC breed page: 140-200 pounds. The calculator uses about 170 lb for males and 170 lb for females as the typical adult weight.
Common questions
How much should a Spanish Mastiff puppy weigh at 3 months?
A typical male Spanish Mastiff weighs about 45 lb at 3 months (most between 33 and 59 lb). A typical female weighs about 45 lb (most between 33 and 59 lb).
How much should a Spanish Mastiff puppy weigh at 6 months?
A typical male Spanish Mastiff weighs about 108 lb at 6 months (most between 87 and 128 lb). A typical female weighs about 108 lb (most between 87 and 128 lb).
How much does a Spanish Mastiff weigh at 1 year?
A typical male Spanish Mastiff weighs about 155 lb at 12 months (most between 134 and 171 lb). A typical female weighs about 155 lb (most between 134 and 171 lb).
When does a Spanish Mastiff stop gaining weight?
The typical Spanish Mastiff puppy reaches about 90% of its adult weight around 12 months and 95% around 18 months. Large and giant breeds fill out for longer than small ones.
How accurate is the Spanish Mastiff weight calculator?
Across our test dogs the typical miss was about 11% of adult weight, smaller for older puppies. Your puppy can land outside the range. See the methods page.
Other breeds
Weight standard: AKC breed page. Growth curves: our analysis of open data from Salt et al. (2017), CC BY 4.0. An estimate, not veterinary advice. Methods.