Toy (Under 12 lbs adult)
Small (13 – 25 lbs adult)
Medium (26 – 50 lbs adult)
Large (51 – 90 lbs adult)
Giant (Over 90 lbs adult)
Estimated Adult Weight
Understanding Your Puppy's Growth Rate
Watching a puppy grow is one of the most exciting parts of pet ownership, but it often leaves owners asking: "How big will my puppy get?" Growth rates vary significantly based on breed size, genetics, and nutrition. While most small breeds reach their full size by their first birthday, giant breeds like Great Danes or Mastiffs can continue to fill out until they are two years old.
How the Puppy Growth Calculator Works
Our calculator uses a specific growth curve formula tailored to breed categories. Generally, puppies grow most rapidly between birth and 6 months. To provide an accurate estimate, we use the following standard logic:
Small & Toy Breeds: They reach roughly 50% of their adult weight by 3-4 months.
Medium Breeds: They reach roughly 50% of their adult weight by 4-5 months.
Large & Giant Breeds: They grow more slowly and steadily, reaching 50% of their adult weight around 5-6 months.
Puppy Growth Chart by Breed Type
Breed Size
Adult Weight Milestone
Full Maturity Age
Toy
Weight at 6 weeks x 4
9 – 10 Months
Small/Medium
Weight at 14 weeks x 2.5
12 Months
Large
Weight at 6 months x 2
18 Months
Giant
Weight at 6 months x 2 + 10%
24 Months
Factors That Influence Growth
While math provides a great estimate, several environmental factors can alter the final result:
Nutrition: Overfeeding can lead to rapid bone growth which may cause joint issues, especially in large breeds.
Spaying/Neutering: Early desexing can sometimes result in slightly taller dogs because the growth plates take longer to close without sex hormones.
Genetics: Looking at the parents is always the most accurate predictor of final size.
Example Calculation
If you have a Medium breed puppy that weighs 15 lbs at 16 weeks old: