Dog calorie calculator

Every number on this page is built from a body weight. For a dog at a healthy weight that works. For an overweight dog it is a trap: type in today’s heavier weight and you get the calories that keep the dog that heavy. The heavier the dog, the bigger the portion the sum recommends. Veterinary guidelines say to calculate from ideal body weight: AAHA (2021) says weight-loss calculations should be based on ideal weight, and FEDIAF (2025) says energy needs should be based on optimal body weight, because the scale alone does not tell you whether a weight is healthy.

A weight-reduction plan is a job for your own vet. Your vet checks that your dog is well, agrees the target weight, picks a food that stays nutritionally complete on fewer calories, and weighs your dog along the way. Do not halve the food and hope.

1. Resting energy. RER = 70 × (weight in kg)^0.75. RER is the energy a healthy dog uses lying quietly. It rises with weight to the power 0.75, not in a straight line: a 40 kg dog needs about 1.7 times the energy of a 20 kg dog, not twice. This is the formula in the AAHA 2021 guidelines (Box 1) and the Merck Veterinary Manual, which says it can be used at any body weight.
2. Daily energy. kcal a day = RER × factor. The factor depends on neuter status, activity and age (table below). Use the dog’s healthy weight.
3. Grams of food. grams a day = kcal a day ÷ (kcal per kg of the food) × 1,000. If your label gives kcal per 100 g, multiply by 10 to get kcal per kg.
4. Meals and treats. Divide the grams by the number of meals. Treats, chews and training rewards together should stay under 10% of daily calories (AAHA 2021, WSAVA, Merck), and they come out of the day’s food, not on top of it.

Each figure is rounded to a whole number and the next step starts from the rounded figure, so you can repeat the sums with a calculator and get the same answer. Grams are worked out from the kcal shown, not from an unrounded value behind the scenes.

The same calories become very different amounts of food. Here is the neutered 20 kg dog from the example (1,059 kcal a day) on foods of different energy.

A scale tells you weight. It does not tell you whether the weight is healthy. Vets use the 9-point body condition score (BCS) from the WSAVA and FEDIAF guidelines. The aim for most dogs is 4 to 5 out of 9, which can look “too thin” to owners used to well-fed dogs.

To estimate a healthy weight, divide today’s weight by (1 + the percentage over). A 30 kg dog scoring 7 is about 20 to 30% over ideal, so its healthy weight is roughly 23 to 25 kg. The calculator above does this for scores 6 to 8. Use the WSAVA body condition chart for dogs to compare your dog with the pictures.

Bruno is a neutered Indie male, 20 kg, a healthy shape (BCS 5), with two walks and some play a day. His food is a dry kibble printed at 3,500 kcal per kg. Neutered adult, normal activity: factor 1.6.

1. Resting energy: 70 x 20^0.75 = 662 kcal
2. Daily energy: 662 x 1.6 = 1,059 kcal
3. Food: 1,059 kcal / 3,500 kcal per kg x 1,000 = 303 g a day
4. Per meal: 303 g / 2 meals = 152 g
5. Treat allowance: 10% of 1,059 = 106 kcal, which is 30 g of this food

So Bruno eats about 303 g a day: 152 g morning and evening. If he gets the full 106 kcal treat allowance he eats 273 g of kibble instead. If the kibble costs ₹450 a kg, 303 g is about ₹136 a day. After two weeks Bruno is weighed. If he is unchanged and his ribs are still easy to feel, the number is right.

Check the power formula against the shortcut some books use, 30 × weight + 70: for 20 kg the shortcut gives 670 kcal, against 662 from the power formula. They are close in the middle of the range and drift apart at the ends (see the questions below).

A factor of 1.6 means “60% more than resting”. It is an average taken across many dogs, not a measurement of yours. WSAVA’s nutritional assessment guidelines say energy needs can differ from a formula by up to 30% either way in dogs, so treat the figure as the first guess in an experiment.

1. Feed the calculated amount, weighed on kitchen scales, for 2 to 4 weeks. Count every treat.
2. Weigh your dog every 2 weeks on the same scale at the same time of day (Merck suggests 2-weekly weighing during weight management). A bathroom scale works: weigh yourself holding the dog, then alone, and subtract.
3. Check the ribs. If weight is creeping up or the ribs are getting harder to feel, cut the food by about 10%. If your dog is losing weight without a plan or the ribs show, increase by about 10%. Change in steps of about 10%, not more, and re-check after another 2 weeks (the step size used by Hand et al. inSmall Animal Clinical Nutrition).
4. If your dog loses weight and you did not intend it, or has an odd appetite, drinks more or seems unwell, see your vet. A change in the numbers is a reason to look at the dog, not only the bowl.

The factor method comes from AAHA and the Merck Veterinary Manual. FEDIAF, the European pet food federation, publishes separate equations built from feeding studies. For a neutered adult at normal activity, FEDIAF’s figure is 110 kcal per kg^0.75 (Table VII-7, 1 to 3 hours of low-impact activity a day). WSAVA also prints a one-page chart of ranges for a healthy adult dog in ideal body condition.

Other checks. For a dog on a weight-reduction plan, AAHA (2021) reports mean intakes of 63 kcal per kg^0.75 (plus or minus 10) in recent programmes. Our weight-reduction figure is 1.0 × 70 = 70 kcal per kg^0.75, which is inside that spread. FEDIAF’s figure for a light-activity dog is 95 and for 1 to 3 hours of high-impact activity is 125; for dogs over 7 years it is 95 (range 80 to 120). The tool above shows the matching FEDIAF figure under each result.

This is general information for healthy adult and senior dogs. It does not apply to:

• Puppies under about 18 months. They use a different equation. See the puppy food calculator.
• Pregnant or nursing bitches. Needs rise sharply (AAHA 2021 gives 3.0 times resting in the last 3 weeks of pregnancy and 3.0 up to 6.0 or more in nursing). Ask your vet.
• Sick dogs and dogs recovering from surgery, or on long-term medicines: kidney, liver or heart disease, diabetes, pancreatitis, thyroid disease, cancer and many others change both the calorie target and the right food. If your dog has a diagnosed condition, or is on a prescription diet, follow your vet.
• Very active working dogs (herding, searching, racing, long runs). AAHA gives 5 to 11 times resting for heavy work and FEDIAF gives 150 to 175 kcal per kg^0.75 for 3 to 6 hours of work a day. The “working” option here covers up to a few hours of hard exercise, not that.
• Breeds far from the average. FEDIAF lists Great Danes at about 200 kcal per kg^0.75 and Newfoundlands at about 105, against 110 for a typical dog. Feed to the ribs and the scale, and let your vet advise.
• Flat-faced breeds such as Pugs. See our Pug diet chart, which is written for the breed.
• Home-cooked food. The calculator only gives calories. AAHA (2021) notes that most published home-cooked recipes, even those written by vets, are not complete and balanced, and recommends a board-certified veterinary nutritionist. If you cook for your dog, ask your vet for a recipe written by one.

Related: Labrador diet chart · Pug diet chart · all diet charts · cat calorie calculator.