PetGrit

Puppy Adult Weight Predictor

Want to know how big your puppy will get? Enter their current weight and age and we’ll estimate their adult weight two ways — a universal growth-rate estimate, plus a size-class milestone estimate if you know whether they’ll be small, medium, large, or giant.

Estimated adult weight

— lb

How to use it

  1. 1 Enter your puppy’s current weight in pounds and age in weeks.
  2. 2 Optionally pick their expected adult size class for a second, breed-aware estimate.
  3. 3 Read the predicted adult weight and a realistic range.

Why this matters

Adult size decides the crate, harness, bed, and food you should buy — getting it roughly right saves money and a lot of returns. The universal method projects current growth rate to one year; the milestone method scales known puppy-growth ratios by size class. Predictions are typically within about 10–20% for purebreds and wider for mixes.

Frequently asked questions

How accurate is a puppy weight prediction?

For purebred puppies at a sensible age, milestone methods land within roughly 10–20% of adult weight. Mixed breeds vary more because growth pattern depends on the mix. Treat the result as a range, not a promise.

When do puppies stop growing?

Small breeds finish around 10–12 months, medium around 12–14 months, large around 14–18 months, and giant breeds 18–24 months. Bigger dogs grow for longer.

What if I don’t know my puppy’s breed or size class?

Use the universal estimate, which only needs current weight and age. A dog DNA test can confirm the breed mix and likely adult size if you want more certainty.

Keep going

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