Feeding requirements depend on the amount of exercise, age, breed, environmental factors, neutered status and individual variation.

We recommend feeding your adult dog or cat 2-3% of his ideal body weight a day, divided into two meals.
We recommend feeding your puppy dog or kitten 5-7% of his ideal body weight a day, divided between meals.

This can be used as a general guide, together with good sense and experience.
For overweight dogs & cats, daily amounts should be based on target weight not actual weight.