Calculate a starting range using age, weight, activity, body condition, and the current food.
Every dog's daily energy requirement starts from body weight, then gets adjusted for the things that actually change it: life stage, neuter status, activity level, and current body condition.
The baseline uses the standard resting energy requirement formula (70 × body weight in kg^0.75) referenced by Tufts and WSAVA, then applies a life-stage multiplier following the AAHA framework. A neutered adult dog at normal body condition sits near the bottom of the range; an intact working dog or a growing puppy sits well above it.
Where you select your exact food, the gram or cup amount is calculated from that product's published calorie content. Where you don't, we use an average calorie density for that food type — and the result tells you which one it used, so you know how much to trust the number.
What this gives you is a starting point, not a prescription. Two dogs of the same weight and age can differ by 25% in what they actually need. The correct way to use this number is to feed it consistently for two to three weeks, then check body condition by hand — ribs easily felt under a thin layer of fat, visible waist from above. Adjust from what you observe, not from what the calculator said.
When not to use it: dogs with kidney disease, pancreatitis, diabetes, or any diagnosed condition affecting metabolism need a diet plan from a veterinarian, not a general calculator. The same goes for any dog currently losing weight without explanation.