Dog Food Calculator
Weight and life stage in — daily calories and cups out, from the same RER formula veterinary nutrition texts use. Ask your vet for the final word.
The short answer
Formula. Daily calories = 70 × (weight in kg)^0.75 × life-stage factor (1.6 for a neutered adult dog).
Example. A 22-lb (about 10 kg) neutered adult: 70 × 10^0.75 × 1.6 ≈ 629 kcal a day — about 1.68 cups of a 375-kcal-per-cup food.
How the math works
Veterinary nutrition estimates energy needs in two steps. First the resting energy requirement (RER) — the calories a dog burns just existing: RER = 70 × (body weight in kg)^0.75. A 22 lb dog is about 10 kg, and 70 × 10^0.75 ≈ 394 kcal — the daily budget of a dog asleep on the couch. Then a life-stage factor scales it: about 1.6 for a neutered adult (the most common pet), 1.8 for intact, 1.0 under veterinary weight-loss plans, 2.0–3.0 for growing puppies, and 2.0–5.0 for true working dogs. Our 22 lb neutered example lands at 1.6 × 394 ≈ 630 kcal per day.
Cups come from the bag, not the dog: every food has a caloric density (typically 300–500 kcal per cup) printed near the feeding chart, and dividing the daily calories by it gives volume — 630 kcal at 375 kcal/cup is about 1.7 cups, usually split into two meals. This is why "how much do you feed her?" is a meaningless question between different foods: the same dog can need two cups of one kibble and three of another. Treats count inside the daily budget (the common cap is 10% of calories), and a proper 8-oz measuring cup — not a mug, not a scoop — is the only honest measuring instrument.
The honest limits of the arithmetic: the formula estimates the average dog's metabolism, and individuals vary by ±20% around it — metabolism, breed, neuter status, indoor temperature and age all shift the real number. That is why feeding charts, this calculator, and your vet all give starting points, not verdicts. The ground truth is body condition: ribs you can feel but not see, a visible waist from above, a tucked belly from the side — checked every couple of weeks, with portions adjusted in 10% steps. Sudden appetite loss, unexplained weight change, or any diet question about a sick dog, a pregnant bitch, or a large-breed puppy belongs with a veterinarian, not a calculator.
Sources & review date
- RER = 70 × kg^0.75 and the life-stage factors are the standard veterinary nutrition equations.
- Calorie arithmetic only — a veterinarian sets an individual dog's real plan.
Last reviewed: October 2026. Numbers that drift (fees, prices, densities) are editable inputs on this page.
Feeding FAQs
How many times a day should I feed my dog?
Two meals for adults; three to four for puppies under six months. Splitting the day's cups evenly matters more than the clock — and measured cups, not free-pouring.
The bag says feed more than this calculator. Who's right?
Bag charts are rounded, and err toward generous. Run your dog's body condition for a month against whichever number you follow; if the waist is disappearing, the smaller number was right.
How do I switch foods without stomach upset?
Transition over 5–7 days: 25% new food, then half, then 75%, then all. The cup math changes with the new kcal-per-cup — re-run the calculator with the new bag's number.
Is this calculator suitable for cats?
No — cats have different energy scaling and specific health rules around fasting and weight loss. Feline feeding math needs its own factors and a vet's supervision for diet changes.