As with humans, the individual requirement for your pet will depend on the type of diet fed, the amount of exercise your pet gets and your pet’s individual metabolism.
There are also other factors that influence energy requirements such as lactation, medical conditions or infections, recent surgery or injury. Growing puppies and working dogs require more energy as well.
The first thing to note, is that the very best way you can determine how much your dog should eat, is by regularly weighing them. Once you know your dogs ideal body weight, you can increase or decrease intake accordingly.
This food calculator link is a great place to start: