How we calculate
Portiopet only uses fixed, published formulas. No AI decides amounts. As of October 23, 2026.
Energy needs
Resting energy = 70 × body weight in kg to the power of 0.75 (kcal per day). For maintenance we multiply by a factor: dog intact 1.8, neutered 1.6; cat intact 1.4, neutered 1.2. Low activity subtracts 0.2, high activity adds 0.2.
Calories from the label
If the calories are on the bag, we use them. Otherwise we calculate them from crude protein, fat, fiber, ash and moisture with the National Research Council (2006) equations as described in the FEDIAF guidelines 2025. Missing moisture: we assume 10%. Missing ash: 7% of dry matter.
Weight loss
We start with the maintenance amount for the target weight (dog 1.4 × resting energy, cat 1.0 × resting energy). It only goes down after weigh-ins, in 10% steps, and never below 0.8 × resting energy at the target weight. Safe pace: dog 1–2%, cat 0.5–2% per week.
When we don’t calculate a plan
For dogs under 18 months, cats under 12 months, pregnant, nursing or ill animals, and for a target weight 20% or more below the current weight. Then your vet can help.
Treats
No more than 10% of daily calories.
Sources
Portiopet is not a substitute for advice from your vet. Every amount is a starting point – the scale has the final say.