Instructions
Begin with the breed of dog in question. Various breeds grow at different rates. Smaller sized dogs mature a little quicker, reaching 99 percent of adult weight between 9 and 10 months of age. The larger breeds don't reach that stage of adult weight until 11 to 15 months of age.
Determine the age of the dog and its rate of growth to calculate the ideal adult weight. A small dog gains about 5 ounces per week from 6 weeks of age, whereas a large breed gains about 2.5 lbs. As a result, it is estimated that a small dog would gain approximately 1 1/4 lbs. per month, while a larger dog would gain about 6 1/4 lbs. per month.
Double the weight of a 6-week-old tiny or toy breed of dog, and then double it again, and you will get an estimate of what the adult dog will weigh. If your tiny dog weighed 2 lbs. at 6 weeks old, the weight calculation would be 2 x 2 x 2 for an estimated ideal weight of 8 lbs.
Take the weight of a larger breed of dog at the age of 14 weeks and multiply that weight by 2, and then add another half of the 14-week-old weight to estimate the ideal adult weight. For example, if your larger dog weighs 20 lbs. at 14 weeks old, the calculation would be 20 x 2 +10 for an estimated ideal adult weight of 50 lbs.
How to Calculate the Ideal Weight for a Dog
It is important to monitor your dog's weight to be sure he is growing on track for his size, breed and build. Obesity can be as serious a problem with dogs as it is with humans. Another concern may be if your dog is getting the proper nutrition. There are several ways that you can calculate the ideal weight of your dog.