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Dog & Cat Food Portion Calculator
Exactly how much food? The real veterinary formula, not a guess from the bag.
What's the formula behind this number?
This tool uses the standard veterinary formula: first the resting energy requirement (RER) is calculated from body weight, then it's multiplied by a standard activity factor based on the pet's life stage (growth, neutered, active, senior or weight loss) to get the real daily energy need, the maintenance energy requirement (MER). Finally, that energy is converted into grams of food based on the energy density printed on your food bag.
Why do I need to enter the food's energy from the package?
Different foods have very different energy densities — a rich, high-calorie food delivers the same energy in a smaller amount, while a lower-calorie diet food needs a larger volume to supply the same energy. Take the kcal-per-100g figure from your own food's label for an accurate result.
Frequently asked questions
How accurate is this formula?
The RER/MER formula is the standard baseline in veterinary nutrition and a good starting point for most healthy dogs and cats, but every animal's real needs can vary somewhat — check your pet's weight every few weeks and adjust the amount accordingly.
What if I feed wet (canned) food?
The same method works — just enter the kcal-per-100g figure printed on the wet food package; because wet food usually contains more water, it's typically less energy-dense per 100g and a larger gram amount is needed.
Why does a neutered/spayed pet need less food?
Neutering/spaying usually lowers baseline metabolism a bit, so the activity factor for a neutered/spayed pet is set somewhat lower than for an intact one, to help prevent excess weight gain.
What if my pet is overweight or underweight?
Choose the "Weight loss" option for gradual, controlled reduction, but for a precise diet plan — or if the excess weight is severe — always talk to your veterinarian.