How pet food portion calculator works
The calculator starts from the standard veterinary energy model. The Resting Energy Requirement (RER) — the calories a pet burns at complete rest — is 70 × (bodyweight in kg)^0.75. That resting figure is then multiplied by a life-stage factor to get the Maintenance Energy Requirement (MER): 1.6 for a neutered adult, 1.8 for an intact adult, 2.0 for working dogs, 3.0 for very young puppies, and 1.0 for a weight-loss plan. These factors follow the WSAVA-style table used across veterinary nutrition.
Calories become grams through the energy density printed on every food label. Most labels state kcal per 100 g (or per cup); divide the daily kcal target by the food's kcal per gram and you get the daily amount in grams, then split it across your chosen number of meals. A 10 kg neutered adult needing 630 kcal of a 350 kcal/100 g food eats about 180 g per day, or 90 g per meal twice a day.
The result also reserves a treat budget: veterinary guidance says treats should stay at or below 10% of daily calories, and the tool shows that cap explicitly. Everything runs in your browser, and the numbers are estimates — individual pets vary with metabolism, activity and health, so treat the result as a starting point to review with your vet, especially for weight-loss plans or growing puppies.