Energy is required for the body to function and is usually reported in kcal per day or kcal per gram of food.

What is a calorie?

A calorie is a measure of the energy needed to heat 1 gram of water 1 degree (from 14.5 to 15.5 °C). The term “calorie” is being replaced by the term “joule” in the metric system (4.18 joules equals 1 calorie).

What is a kcal?

A kcal, or kilocalorie, is 1000 calories. This is the most common unit of energy used to express an animal’s daily requirement and the caloric density of pet foods. The average ten pound cat, for example, requires about 250 kcal per day, and the average thirty pound dog requires about 750 kcal per day. Most of us eat more than 2000 kcal per day!

Determining the energy requirement of your pet is a bit more difficult, however, and can vary with your pet's age and condition.
If your pet is an adult, neutered, and inactive (not racing, working, or otherwise active) animal, click on the calculator to estimate your pet's maintenance energy requirement.

What is caloric density?

Caloric density is the energy concentration in a food expressed as kcal per gram of food, but it is most often converted to kcal per can or per cup of food for pet owners.

Determining the caloric density of a food can be done by several methods and is not particularly difficult for nutritionists. The caloric density is now allowed—not required—but must be reported in readily understandable units: kcal/can or kcal/cup. If the caloric density is not reported on your pet food's label, the information can be obtained from the manufacturer.

Determining the amount of food to feed daily can be estimated several ways. The feeding guidelines on the pet food label should only be used as a starting point.
Click on the calculator to figure out how much food to feed your pet based on his or her maintanence energy requirement (MER) and the caloric density of his or her food.

Each pet should be individually fed, and the amount of food must be adjusted for the pet’s breed, age, and activity level. Estimates of your pet’s caloric requirement and amount of food to be fed should be taken as just that—estimates. If your adult pet is gaining weight, the amount of food fed should be reduced by 25%, or if your pet is losing weight, increase the amount of food by 25%. Re-weigh the pet in two weeks and readjust the food amount again as needed.

Sound complicated? If you need help feeding your pet the right amount of food per day, click on Ask the Nutritionist.