You might have to call the dog food company to get the number of kilocalories per gram of food, or you can check out Ohio State's web site on nutrition, which might have your dog food listed (I think we have a link to this on our link page). (vetinfo.com)
A dog food that is complete and balanced and includes at least 26 percent protein and 1650 kilocalories of metabolizable energy per pound is ideal. (dogbreedz.com)
Pet foods labeled as light, lite, or low - calorie must list calorie concentration in kilocalories per cup on the label. (articles.extension.org)