Homemade Dog Food Calorie Calculator
Enter your dog's weight and your batch's kcal per 100 g — and get grams a day and grams per meal. The formula and every coefficient are printed below.
Feed per day
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Enter a weight and a batch density to see the answer.
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Everything is calculated in your browser. The numbers you type are not uploaded and not stored.
The formula, printed in full
Every number this page produces comes from two published pieces of arithmetic. Nothing here is proprietary, and nothing is hidden behind a login.
RER = 70 × (body weight in kg)^0.75 resting energy requirement MER = RER × life-stage factor maintenance energy requirement kg = lb × 0.45359237 grams per day = MER ÷ (kcal per 100 g) × 100 grams per meal = grams per day ÷ meals per day
The exponent form 70 × kg^0.75 is the standard allometric resting-energy equation. The
life-stage factor is the band that turns a resting requirement into a daily feeding target: a typical
neutered adult sits at roughly 1.4–1.6 × RER, an intact adult around 1.6–1.8,
and a working dog higher still.
The step that most homemade calculators skip is the last one. A calorie target is not a portion size until you divide it by the calorie density of the actual food in the bowl. If your batch is 150 kcal per 100 g, then a 900 kcal day is 600 g. If the same recipe is denser — say 180 kcal per 100 g — the same 900 kcal day is only 500 g. The target never changed; the scoop did.
Why energy density decides the portion
Two homemade batches can look identical in the bowl and differ by half in calories. That is why this page asks for kcal per 100 g instead of guessing from the ingredient list.
Work the numbers for a 40 lb neutered adult. In kilograms that is 40 × 0.45359237 = 18.144 kg.
Resting energy is 70 × 18.144^0.75 = 615 kcal. The neutered-adult band multiplies that to
862–985 kcal a day (mid 923). At 150 kcal per 100 g that is 574–656 g a day;
split across two meals, 287–328 g per meal.
Now keep the dog and the calorie target identical, and change only the batch. At 120 kcal per 100 g the
same day becomes 718–821 g. At 180 kcal per 100 g it becomes 479–547 g. Same dog,
same day, a scoop that moves by more than 200 g — because the food changed, not the dog.
This is an estimate, not a prescription. Individual dogs vary, and long-term home feeding should be reviewed with your veterinary team.