Mastiff Weight Chart
How big do Mastiffs get? See their growth chart and ideal weight.
Quick Answer
The Mastiff is a giant-sized dog that typically weighs 90-105 lbs. They reach full adult size by approximately 18-24 months. See the complete growth chart and weight milestones below.
Mastiff Growth Chart
Is My Mastiff a Healthy Weight?
A healthy Mastiff should have a visible waist when viewed from above, and you should be able to feel (but not see) their ribs. Proper nutrition and regular health checkups are essential for maintaining your Mastiff's ideal weight.
- ✓Ideal: Ribs easily felt, visible waist, tucked abdomen
- !Overweight: Ribs hard to feel, no waist visible, rounded belly
- ✗Underweight: Ribs, spine visible, prominent waist
Frequently Asked Questions
How big does a Mastiff get?
A healthy adult Mastiff typically weighs between 90-105 lbs. They are considered a Giant breed.
When does a Mastiff stop growing?
Most Mastiffs reach their full adult height and weight by 18-24 months. However, they may continue to "fill out" with muscle for a few months after.
How much should a Mastiff puppy weigh at 3 months?
At 3 months old, a typical Mastiff puppy weighs approximately 29.3 lbs. Growth rates vary, so consult your vet if concerned.
How can I tell if my Mastiff is overweight?
A healthy Mastiff should have a visible waist when viewed from above, and you should be able to feel (but not see) their ribs through a thin layer of fat. If the waist isn't visible, ribs are hard to feel, or the belly sags, your Mastiff may be overweight. Consult your vet for an accurate body condition assessment.
Official Breed Standards
For official Mastiff size and weight standards, refer to the AKC Breed Standards. Breed standards define the ideal size range, but individual dogs may vary based on genetics, diet, and overall health.