How Many Calories Does My Dog Need Each Day?

How the daily calorie formula for dogs works, why life stage matters, and how to turn calories into cups of food.

Most feeding charts on dog food bags give a range by weight, but they cannot account for your dog's age, activity, or whether they have been spayed or neutered. The method vets use starts with calories and works backward to a portion.

Step 1: Resting energy requirement (RER)

RER is the energy a dog needs to stay alive while resting: breathing, digestion, keeping warm. The standard formula is:

RER = 70 × (body weight in kilograms)^0.75

Weight in pounds divided by 2.2 gives kilograms. A 20-pound dog weighs about 9.1 kg, which works out to an RER of roughly 366 calories per day.

Step 2: Multiply for life stage and activity

Dogs do more than rest, so RER is multiplied by a factor. These are the factors our calculator uses:

The 20-pound neutered adult from above needs about 366 × 1.6, or roughly 585 calories a day.

Step 3: Turn calories into a portion

Divide the daily calories by the calories in a cup of your dog's food. Find that number on the bag; our guide to reading a dog food label shows where. At 380 kcal per cup, 585 calories is about 1.5 cups a day, or three-quarters of a cup at each of two meals.

Why it is only a starting point

These formulas describe an average dog. Two dogs of the same weight can differ by 20 percent or more in what they actually need, depending on metabolism, breed, coat, and daily exercise. Treat the result as your starting amount, then check your dog's body condition every few weeks using our healthy weight check. If your dog is gaining weight, reduce the amount by about 10 percent. If they are losing weight and should not be, increase it slightly.

Remember to count treats and any food used for training in the daily total. See dog treats and calories.

Dogs with health conditions, and pregnant or nursing dogs, have different needs. Ask your vet.

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