Use this Neapolitan Mastiff puppy weight calculator to predict how big your puppy will get. Neapolitan Mastiffs are a giant working breed that keeps growing until around 18-24 months.
Enter your puppy's current weight and age to predict their adult size
Estimates based on breed growth curves. Individual dogs vary with genetics and nutrition — check with your vet for a personalized read.
Slows fast eaters, can aid digestion, holds 4 cups dry or wet food — sized for giant breeds.
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| Age | Weight |
|---|---|
| Birth | 2 to 5 lbs |
| 2 Months | 9 to 15 lbs |
| 3 Months | 17 to 30 lbs |
| 4 Months | 28 to 45 lbs |
| 5 Months | 39 to 60 lbs |
| 6 Months | 50 to 75 lbs |
| 7 Months | 61 to 90 lbs |
| 9 Months | 72 to 105 lbs |
| 10 Months | 83 to 120 lbs |
| 1 Year | 94 to 135 lbs |
| 1.5 Years | 105 to 150 lbs |
| 2 Years | 110 to 150 lbs |
Estimated from typical giant-breed growth curves and the Neapolitan Mastiff's adult weight range. Individual puppies vary — use the calculator above for a prediction based on your puppy's actual current weight.
New breed data, growth tips, and puppy-parenting insights, plus our free printable puppy growth tracker.
As a giant breed, Neapolitan Mastiffs are predisposed to hip and elbow dysplasia, heart problems, and bloat. The deep facial and body wrinkles need regular cleaning to prevent skin fold infections — a genuine, ongoing care requirement given how central the wrinkles are to the breed.
A large-breed puppy formula through the growth period; adults need substantial food given their size, with portions split to help reduce bloat risk.
The short coat needs minimal brushing, but skin fold cleaning is a real daily-to-weekly task given the breed's wrinkled build.
Neapolitan Mastiffs are intensely loyal but naturally wary of strangers and prone to separation anxiety — uncommon for a giant breed. Early socialization and consistent training matter given the breed's eventual size and protective instincts; this is not a breed for a first-time owner.
The Neapolitan Mastiff descends from ancient guard-dog lineages of southern Italy, related to war and guard dogs used since Roman times, but the modern breed was specifically rediscovered and standardized starting in 1946 by Piero Scanziani after he saw one at an exhibition in Naples. The AKC recognized the breed in 2004.
The breed's defining trait — extensive, hanging wrinkles and a voluminous dewlap — is written directly into the standard, considered essential to type rather than incidental; a Neapolitan Mastiff without these folds would be disqualified from showing. Beneath the imposing appearance, the breed is known for calm devotion to family paired with genuine wariness toward strangers.
