How Big Will My Puppy Get?

“How big will my puppy get?” It’s one of the first questions pet parents ask when bringing home a new puppy. While there’s no crystal ball to predict the outcome with absolute certainty, there are several tools that can help.

In this article, we’ll explore ways to tell how big your puppy will get, from breed standards and puppy weight calculators to formulas, genetics, and vet insights. We’ll also look at what affects puppy growth and how you can best support your dog’s healthy development from puppyhood to adulthood.

Estimating Puppy’s Growth: Why it’s Important

If you have a purebred puppy, the breeder can usually tell you about how big your pup is likely to get. Their prediction is based on several factors, including breed standards, parents’ size, and past litters.

If you have a puppy with unknown parentage, however, estimating adult size can be challenging. That’s because additional factors, such as genetic variations and early nutrition, can impact growth patterns.

Despite these challenges, it remains important to know how much a puppy will grow, even if it’s not exact. Even a ballpark estimate can help you: 

• Make sure you have enough space to accommodate your dog
• Choose the right puppy food to support normal growth and development
• Create appropriate exercise routines
• Accurately monitor growth against expectations

How Big Will my Puppy Get? 5 Ways to Find Out

Most pet parents have probably Googled “puppy weight calculator” once or twice. If that includes you, you’ve probably seen a variety of tools promising the answer. These can include things like a puppy growth chart or puppy weight size predictor.

But how accurate are these tools? Is it as simple as plugging some info into How Big Will My Puppy Get Calculator? Is that the best way to figure out how big your puppy is going to get?

Let’s talk about the options available to you.

Puppy Size by Breed Category

If you know your puppy’s breed of origin, you can usually look up the breed standard to see how big your puppy will get. If you adopt a puppy from a breeder, they should have this information for you. 

You can also use general breed size categories to estimate the adult size of your puppy:

Breed Category	Expected Adult Weight
Toy Breed	Up to 10 pounds
Small Breed	10-25 pounds
Medium Breed	25-50 pounds
Large Breed	50-100 pounds
Giant Breed	Over 100 pounds

Note: This doesn’t work as well for mixed-breed dogs with unknown origins or mixed-breed dogs with parents from different breed size categories. 

Formulas for Estimating Adult Size

There are several formulas people can use to try and predict the adult size of a puppy. These formulas typically require knowing your pup’s breed(s) of origin, age, and other factors. Two simple and fairly reliable formulas include:

• Small and Toy Breeds: Multiply (the puppy’s weight at 8 weeks) x 3
• Medium, Large, and Giant Breeds: Multiply (the puppy’s weight at 16 weeks) x 2

However, these formulas do not take additional factors that can influence adult size into consideration. (E.g., spay/neuter status, nutrition, or health issues).

Puppy Growth Calculators

Online puppy growth calculators are widely available. These calculators plug several variables into a mathematical formula to calculate the adult size of a puppy. Factors include puppy breed, current weight, age, and gender.

Keep in mind, the results you may get from a puppy size calculator are general estimates. They typically do not take spay/neuter status, nutrition, or health issues. They also aren’t very accurate if you don’t know your puppy’s breed or age. 

Genetic Panel

Several companies now offer products that allow pet parents to conduct genetic panel testing from home. The results may help predict your puppy’s adult size based on a proprietary genetic algorithm.

Here’s how it works: Using a cheek swab, you collect genetic material from your pup and send it back to the company for analysis. Each company’s methods may vary, but the analysis usually relies on common genetic variants known to affect body size in certain dog breeds.

Though it’s more scientific, a genetic panel is yet another adult-size estimator. It’s not a guarantee based on your pet’s unique genetic profile.

Ask Your Vet

One of the easiest things you can do is ask your vet how big your puppy might get. You already have to take your growing pup in for multiple checkups in their first year. And vets are typically happy to share their extensive knowledge, so just ask!

Your vet also has the distinct advantage of knowing all the history and health details unique to your specific doggo. Many of these factors can affect your puppy’s growth. Plus, they can give you real-time alerts if they see anything unusual in your pet’s growth chart. Since you are already paying for their opinion, it never hurts to ask. 

What Else Impacts Puppy Growth? 

In addition to the above guidelines and tools, there are more ways to estimate your puppy’s eventual size.

One fairly reliable puppy size predictor is the size of a puppy paw. If your puppy has noticeably large paws, they may grow into a large or giant-sized adult. This is a subjective measurement, however. It’s always a good idea to get a second opinion from your vet for accuracy.

Additional factors when considering how to tell how big a puppy will get include:

• How big their parents are
• When your puppy was spayed/neutered (if known) – Dogs that are spayed/neutered earlier tend to be taller and weigh more than dogs that go through puberty with their sexual organs intact
• Quality of prenatal and early nutrition – Puppies that experience early malnutrition tend to be smaller.
• Gender – Male dogs are generally bigger than females
• Overall health – Puppies with orthopedic, metabolic, or organ disease (such as congenital heart or liver disease) tend to be smaller.

How to Support Your Growing Puppy

While genetics play a big role in the possible adult size your puppy can grow to, other influences can affect your pet’s growth and development.

Here are a few ways to help your puppy grow strong and healthy, so they can achieve whatever adult size they are meant to be.

• Feed your puppy a diet that is labeled “for growth and reproduction” according to the Association of American Feed Control Officials (AAFCO). This is the organization that sets nutrient standards for different stages of life to ensure your pet has what they need to thrive.
• If you have a large or giant breed puppy, feed them large-breed puppy food formulated for joint and bone health. Such diets have different calcium, phosphorus, and calorie levels than regular puppy food.
• Feed your puppy puppy food until they are done growing, then switch to adult food. 
• Avoid high-impact exercises, such as extended running or running on hard surfaces, until your puppy is done growing and their bone growth plates are closed. If you aren’t sure when that is, ask your vet. 
• If you have a large or giant breed dog, talk with your veterinarian about the best time to spay or neuter. Delaying this procedure until they are done growing can lower the incidence of certain diseases. 
• Work with your vet to ensure your puppy is at a healthy weight for their age and breed. Avoid overfeeding or underfeeding your puppy, as both can negatively impact normal growth and development. 
• Understand that your puppy will go through growth spurts where they will be extremely hungry and need more food. Pay attention to your puppy’s appetite and body condition, and alert your vet if you notice anything out of the ordinary. 
• Avoid giving supplements, including joint supplements, until your puppy is done growing. 
• Take your puppy to all their veterinary visits so your vet can track their growth and alert you if anything is abnormal. 
• Ask your vet how much you should be feeding your puppy. 
• Keep internal parasites that can impact growth out of your puppy by deworming them regularly with veterinary-approved dewormers. 

For more guidance on nutrition, check out when to switch to adult dog food.

While no tool can tell you exactly how big your puppy will get, understanding your puppy’s background and using available resources can give you a fairly accurate estimate. By working with your vet and supporting your puppy’s development, you’ll be better equipped to meet their needs—no matter their size.