How to Tell How Old My New Puppy Is

This German shepherd puppy's longer legs put her age at around 12 weeks.
i Jupiterimages/ Images

You’ve just acquired an adorable new furbaby and are bursting to know how old she is. Hopefully, you got her from responsible pet parents and she isn’t too young to leave her mom, but if you found her through some other means she might be very young.

Step 1

Check your puppy’s eyes to see if they are fully open and focused. Puppies open their eyes between 7 and 14 days old and within a few days they start looking around. If your new baby’s eyes are not fully open and clear, she may be very young and require special care and feeding.

Step 2

Open her mouth and examine her teeth, if she has any. If you see a few teeth starting to peek through, you can safely put her age at between 30 and 45 days. If you’re able to see a full set of 28 puppy teeth, she is 45 days or older. Puppies cut their adult teeth from around the third month, while their adult canine teeth only appear fully by 5 months old.

Step 3

Look at the length of your puppy’s legs and the way she moves. Very young puppies stagger and stumble on their feet, but by the age of 8 weeks they are able to scamper around confidently. When she reaches 4 months old her legs are longer and she starts to run properly.

Step 4

Research the breed standard for your puppy on the American Kennel Club’s website to find out what the average height is for her breed and gender. Puppies reach around 60 percent of their full height at 4 months old, and 75 percent by 6 months.

Step 5

Weigh your puppy by standing on a bathroom scale holding her, then weigh yourself without the puppy in your arms. Deduct your own weight from the combined total to get her exact weight. Alternatively, take her to the veterinarian and weigh her on the special dog scale most vets have in their practices.

Step 6

Compare her weight to her predicted adult weight according to the breed standard. If your puppy is one of the small- or medium-sized dog breeds, she will reach 75 percent of her adult weight by 4 months old. Large and giant breeds, however, mature more slowly and only reach 30 percent of their adult weight by this age.

Step 7

Evaluate your puppy’s muscle development, based on the description of her breed’s build. Small- and medium-sized breeds develop their muscles fully by the time they are 12 months old, but large and giant breeds only reach their full size by 18 months old.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

the nest