Dog food calculator
Enter the weight of a dog, its stage and the calories in a cup of its food to see the calories it needs a day, a range that allows for the dog, and the cups of food to give.
This answer is for the example values in the boxes above. Adult, neutered dog of 30 pounds, 350 kcal a cup, 2 meals. Change the boxes to see your own answer.
The resting energy is 70 times the weight in kilograms to the power 0.75, and the daily energy is that times 1.6 for this stage. The manual that gives the formulas calls them a starting point.
It is for a healthy dog. A dog that is ill, underweight, pregnant or nursing, or that has to lose weight, needs a plan from a veterinarian.
How it works
The calculator changes the weight to kilograms (a pound is 0.4536 kilogram), works out the resting energy, 70 times the weight to the power 0.75, in kilocalories a day, and multiplies it by the factor of the stage.
The factors are those of the table in the Merck Veterinary Manual for healthy dogs. They are 1.8 for an adult that is not neutered, 1.6 for a neutered adult, 1.4 for an adult prone to obesity, 3 for a puppy and 2 for a puppy over 4 months. The manual calls the result a starting point, and says that an animal may need as much as 30 percent more or less.
A worked example
A neutered dog of 30 pounds weighs 13.6 kilograms. Its resting energy is 496 kilocalories a day and its daily energy is 1.6 times that, 794. The range of 70 to 130 percent is 555 to 1,032. A food with 350 kilocalories in a cup comes to 2.27 cups a day, which is 1.13 cups in each of two meals.
An intact dog of 60 pounds on a food of 380 kilocalories a cup needs 1,501 kilocalories, which is 3.95 cups. A puppy of 8 kilograms under 4 months on 400 kilocalories a cup needs 999 kilocalories, which is 2.5 cups, or 0.83 cup in each of three meals.
What it is not for
The formulas are for a healthy dog. They are not a plan for a dog that is ill, underweight, pregnant or nursing, or that has to lose weight. A veterinarian decides what such a dog eats. The calculator gives no calories for a cup of food either: they are printed on the package, and they differ from food to food.
Sources
- Merck Veterinary Manual, Nutritional Requirements of Small Animals, read on 2026-11-02.
- NIST Special Publication 811, Appendix B.8: factors for units listed alphabetically, read on 2026-11-01.
Questions
How many calories does a dog need a day?
A veterinary manual gives the resting energy as 70 times the weight in kilograms to the power 0.75. The daily energy is that times 1.6 for a neutered adult, 1.8 for an intact one, 1.4 for one prone to obesity, 3 for a puppy and 2 for a puppy over 4 months. A neutered adult of 30 pounds needs 794 kilocalories.
How many cups of dog food is that?
Divide the calories by the calories in a cup of your food, which the package prints. At 350 kilocalories a cup, 794 kilocalories are 2.27 cups a day, or 1.13 cups in each of two meals.
Is the result exact?
No. The manual calls any such figure a starting point, and says that an animal may need as much as 30% more or less than another of the same weight. The calculator shows that range, 555 to 1,032 kilocalories for the dog above.
Why do cups differ between foods?
The calories in a cup differ from food to food, and the package of your food says how many. The calculator takes the number that you type and gives none of its own.
Can I use this for a sick dog or one that needs to lose weight?
No. The formulas are for a healthy dog. A dog that is ill, underweight, pregnant or nursing, or that has to lose weight, needs a plan from a veterinarian.
Published .