How this calculator works
Puppies of different adult sizes grow at different rates: toy and small breeds reach full size fast (as early as 6–9 months), while giant breeds keep growing for up to two years. Picking a specific breed sets the right growth curve automatically, based on that breed's typical size tier — or choose "mixed breed / not sure" and pick the closest size yourself. The calculator then uses typical growth-curve percentages — what share of adult weight a puppy has usually reached at a given age — to back into an estimated adult weight from your puppy's current weight and age.
Why this is only an estimate
Individual puppies vary, and mixed-breed puppies can be harder to predict than purebreds. Littermate size, sex, and genetics all play a role. Use this as a ballpark figure, and ask your vet for a more tailored estimate at checkups — they can track your puppy's growth curve directly.