📏 Dog Size Calculator
Estimate how big your puppy will get as an adult, based on their current weight, age, and expected size category.
How puppy growth curves work
Puppies of different adult sizes grow at different rates relative to their eventual full size. Small breeds mature fastest and reach close to their adult weight by around 9 months, while giant breeds grow more slowly and may not finish filling out until 18-24 months. Veterinary growth charts express this as the percentage of adult weight reached at a given age.
How this calculator works
Enter your puppy’s current weight, current age in weeks, and expected adult size category. The calculator looks up (and interpolates between) typical growth-curve percentage milestones for that size category, then divides current weight by that percentage to project the likely adult weight.
This is a population-average estimate, not an exact prediction — individual growth varies with genetics, sex, and nutrition. For a more precise projection, parentage and breed-specific growth charts from a veterinarian are more reliable.