While puppies can be super cute, occasionally it can be a bit of a mystery on how big the dog will get when it is an adult. This is especially true if your dog is a variety of breeds.
Puppies typically stop growing after their first year or two (depending on the size of your dog).
| Small Dogs | Tend to hit their adult weight around 6 months |
| Medium-sized Dogs | Will usually peak around the 1 year mark |
| Large Dogs | Typically will grow until they are 2 years old. |
Method 1: Breed Knowledge
First, start with the breed. Your dog’s breed should give you a good idea of how big your dog will get. There is a lot of information about purebred dogs online and I recommend that you take some time to research each breed of your dog to determine the typical maximum size that your dog can become.
If you are lucky, you have know your puppy’s parent. They will provide a fantastic idea of the future size and features of your dog. If you don’t know our pup’s mom and dad (but you know your dog’s breed), you should again research the typical sizes of dogs that are of the same breed as your dog.
Method 2: Weight
If you know your puppy’s exact age, you can easiely estimate how big they will be when they are older. All you need to do is keep track of their weight on a daily basis from birth and leverage a few math equations.
Typically, puppies will double in weight by their one week of age. Meaning if your pup weighed one pound at birth, they should now weight two. And if they weighted two pounds at birth, they should now weight four pounds.
After the first week, your pup’s weight will increase by five to ten percent each day. This five percentage range is typically due to how much they ultimately eat and the puppy’s genetics.
Option 1: Tracking Weight From Birth
Small and Toy Dogs
For small dogs, determining their adult weight is relatively simple. After the 6 week mark, small dogs will continue to put on weight. However, they will not grow as fast as larger dogs. To estimate your small dog’s adult weight, take their weight at 6 weeks old and double it twice.
So for example, if your puppy weighs 3 pounds at 6 weeks. First, double it once to get 6 pounds, then double it again to reach 12 pounds. This means that your pup should approximately weigh 12 pounds when they are an adult.
Medium to Large Dogs
For larger dogs, they will typically continue to gain weight at a 5 to 10 percent rate passed 6 weeks. Then tend to have a significant growth spurt during this time, so expect them to grow faster. In order to estimate their adult weight, you need to look at their weight at 14 weeks of age.
Determining a medium/large dog’s adult weight is a little harder:
- Take their 14-week age and double it.
- Halve the original 14-week age and add that to the previous step.
For example, let’s take a puppy that weighs 18 pounds at 14 weeks old. We’d first double that 18 pounds to 36 pounds. Then, we’d take half of the 18, which is 9, and add it to the 36 for a total of 45. As an adult, this puppy would weigh around 45 pounds.
Option 2: How to Estimate When Birth is Unknown
If you don’t know the day that your puppy was born, you can can still estimate how big your puppy will get when it is an adult. The key is to take note of your puppy weight when it reaches certain milestone ages:
| Small Dog | 12 Weeks |
| Medium-sized Dog | 16 Weeks |
| Large Dog | 20 Weeks |
Step 2: Take your puppy’s weight in pounds at the milestone ages listed above. Then, divide their weight by their age in weeks. Next, multiply this figure by 52 (the number of weeks in the year). The end result will be
* Let’s take a look at a medium-sized dog that weighs 10 pounds at 16 weeks of age.
We’d first divide 10 by 16. This gives us 0.625. We’ll then multiply 0.625 by 52 to get 32.5. This dog would weigh around 32 and a half pounds as an adult.
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We hope this helps! Feel free to list your dog’s adult weight in the comments below.