Dog Size Calculator

Use our dog size calculator to estimate your puppy’s adult weight from age (weeks) and current weight (lb). If you’re wondering “how big will my puppy get?”, this calculator gives a quick adult weight estimate plus tips for interpreting the result.

Your puppy's age (weeks)
Enter your puppy’s age in weeks.
Weight (lb)
Enter your puppy’s current weight in pounds (lb).
Results
Adult weight (lb)
Rule of thumb estimate based on puppy age and current weight.
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How Big Will My Puppy Get?

Estimating how big your puppy will get is most accurate when you use age and current weight. Puppies grow quickly early on, then slow down as they approach maturity, and different breeds grow on different timelines.

This dog size calculator estimates adult weight based on your puppy’s age in weeks and current weight in pounds. The estimate is most useful as a rough range, not a guarantee, because genetics, nutrition, health, and breed mix all affect final size.

For mixed-breed puppies, an adult weight estimate can still be helpful for planning things like food portions, crate size, travel gear, and expected exercise needs.

How to Use the Dog Size Calculator

  1. 1

    Enter your puppy’s age (weeks).

  2. 2

    Enter your puppy’s current weight (lb).

  3. 3

    The calculator estimates your dog’s adult weight (lb).

  4. 4

    Use the result as a planning estimate and re-check as your puppy grows.

Frequently Asked Questions

How big will my puppy get?

A useful estimate comes from your puppy’s age and current weight. This calculator uses those two inputs to estimate adult weight, but genetics and breed mix can shift the final result.

How do I know how big my puppy will get?

The best clues are age + weight trends over time, breed size history (if known), and growth rate. Using a calculator periodically as your puppy grows gives a more realistic picture than guessing from a single snapshot.

Does a puppy’s paw size determine size?

Paw size can be a rough clue, but it is not a reliable predictor on its own. Two puppies with similar paws can still end up different sizes depending on breed, genetics, and body proportions.

Why do dog size predictions change over time?

Puppies do not grow at a constant rate. Growth spurts, breed growth timelines, and changes in nutrition or activity can all affect how quickly weight increases week to week.

When do dogs stop growing?

It depends on breed size. Smaller breeds often reach adult size earlier, while large and giant breeds can keep growing for many months longer.