One of the basic approaches to calculate your dog's Daily Energy Requirements (DER), uses the following formula:
=(70x kg Bodyweight^.75 )/p>
Then multiplier factors, such as 1.6 and 1.8, are applied to the result. Factors vary according to age and activity level. These are not hard and fast numbers though, and it is best to consult with your vet in determining the energy needs of our dog.
This App applies standard factors that are widely used by veterinarians. But there are others, such as the Maintenance Energy Requirement [PDF], that you might also consult.
Christine Zink, DVM, a leading expert on canine sports medicine, provides good thumbnail guidelines: “An inactive dog is one who rarely gets more than a jaunt around the yard, a moderately active dog is one who gets 15 to 30 minutes of continuous exercise every day, an active dog is one who walks twice daily for about 45 minutes each time, and a highly active dog is one who gets at least several hours of exercise every day.”
RER & DER PDF CHARTS: Adult Active Dogs, Adult Highly Active Dogs, Adult (Intact) Moderate Dogs, Adult Moderate Dogs, Puppy: 50% of Adult Weight, Puppy: 50-80% of Adult Weight, Puppy: 80%-100% of Adult Weight, and Highly Active Senior Dogs.