Puppy Weight Predictor Calculator

It uses the growth-percentage method that veterinary and breeder growth charts rely on. At a given age, a puppy has reached a known share of its adult weight, and that share depends on breed size. The calculator divides your puppy's current weight by that share, so adult weight equals current weight divided by the growth percentage. For example, a small-breed puppy at 12 weeks is about 50 percent grown, so a 5 lb puppy projects to roughly 10 lb as an adult.

Breed size changes how fast a dog grows, so the same age maps to a different percentage of adult weight for each class. Small breeds (adult under 20 lb) finish growing by about 12 months, medium breeds (20 to 50 lb) by about 12 to 15 months, and large or giant breeds (over 50 lb) by 18 to 24 months. A 16-week puppy is around 62 percent grown if small, but only about 42 percent if large, which is why choosing the right size matters for the estimate.

It is a reasonable estimate, not a guarantee. The calculator reports a likely range of plus or minus 10 percent around the point estimate to reflect normal variation. Accuracy improves as your puppy gets older, because more of its growth has already happened. Predictions made before 8 weeks are flagged as low-confidence, since the growth share is small and a few ounces swing the result a lot.

Enter your puppy's current age in weeks or months and its current weight in pounds or kilograms. The tool accepts ages from 1 week up to 104 weeks (about 24 months). For the tightest estimate, weigh your puppy on the same scale you would use for yourself, holding the puppy and subtracting your own weight if needed, and recheck every few weeks as it grows.

Yes. For a mix, estimate the adult size from the parents or from your veterinarian's guess and pick the closest size class. If you are unsure whether your dog will land small or medium (or medium or large), run both and treat the two results as the low and high ends of the range. Paw size and parent weight are useful clues, but they are rough.

No. This calculator is for general education and planning, such as buying the right size crate or estimating food costs. It does not account for your dog's health, body condition, or breed-specific growth patterns. For a target adult weight, growth concerns, or a feeding plan, ask your veterinarian, who can assess your individual puppy.