Puppy weight calculator: how big will my puppy get?

Puppies do not grow in a straight line. Small breeds sprint through growth and are nearly finished by nine or ten months. Giant breeds grow for up to two years and are only about half their adult weight at six months. The calculator uses a separate growth curve for each size class and, when you pick a breed, stretches that curve to match the age at which the breed usually reaches adult size.

Your puppy’s weight today is compared with where the curve says it should be at this age, and the result is scaled up to adulthood. Because every puppy has growth spurts and plateaus, we show a range of plus or minus 10 percent rather than a single number.

Before 12 weeks, small differences in weight swing the result a lot. Mixed breeds follow the size class of their larger parent more often than people expect. And a puppy that is currently too thin or too heavy will throw the projection off in the same direction.

If you know the parents, their weights are the best single predictor. Use the calculator as a second opinion, and weigh your puppy every two weeks to see the curve take shape.