Feeding guides on the packet are broad, and two dogs of the same weight can need very different amounts. Vets estimate energy needs from body weight, life stage and activity, then adjust to the dog in front of them.
This calculator uses the same starting point. It estimates a resting energy requirement from weight and applies published life-stage and activity multipliers to give a daily calorie range. If you enter the energy density of your food, it converts the range to a daily quantity. The packet guidance and your vet’s advice take precedence over any figure here.
