Energy Calculator is an application designed for veterinarians as well as veterinary students, nurses, technicians and nutritionists. It calculates the estimated energy density of dog or cat food from its proximate analysis. - You enter the diet proximate analysis.- You obtain the metabolizable energy density estimated according to the NRC 2006* equation (crude fibre and total dietary fibre, cat or dog), the Atwater and the modified Atwater equations as well as the gross energy. - You obtain the relative contribution of macronutrients to the calories (% of metabolizable energy) based on the modified Atwater equation. - You select one energy density and you obtain the amount/energy ratio of the main nutrients (mg/Mcal or mg/MJ).*National Research Council. Nutrient Requirements of Dogs and Cats. Washington, DC: The National Academies Press, 2006.