Dog Food Portion Calculator
How many cups of kibble your dog should eat per day, worked from its weight, activity level and the food's calorie density.
How it works
RER = 70 × (kg)^0.75 · daily calories = RER × activity factor · cups/day = daily calories ÷ kcal per cup
A dog's daily food is driven by calories, not by a flat cup count. The resting energy requirement (RER) scales to metabolic body weight — 70 × weight in kg raised to the 0.75 power — and is then multiplied by an activity factor to give the maintenance energy requirement. Dividing that by the calories per cup printed on the bag turns energy into a real scoop size, which is why two foods of the same weight can call for very different portions.
Worked example
A 30 lb (13.6 kg) neutered adult has RER = 70 × 13.6^0.75 ≈ 496 kcal, and with a 1.6 activity factor needs ≈ 794 kcal/day. On a 360 kcal/cup kibble that is 794 ÷ 360 ≈ 2.2 cups a day, or about 1.1 cups per meal twice daily.
Frequently asked questions
Where do I find the kcal per cup?
It is on the pet-food bag, usually near the feeding guide, listed as "metabolizable energy" in kcal/cup or kcal/kg. If only kcal/kg is given, divide by the grams in one cup of that kibble (often about 110–120 g).
Should I feed once or twice a day?
Most adult dogs do best on two meals a day, which keeps energy steadier and reduces bloat risk in large breeds. Split the daily cups evenly; puppies need more frequent meals.
My dog is gaining or losing weight — what do I change?
These are starting estimates. Weigh your dog every couple of weeks and adjust the portion up or down by 10% at a time until weight holds steady at a healthy body condition.
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This calculator is for educational purposes. Double-check important results before acting on them.