Free tool
Dog food calculator
Work out your dog's daily portion with the formula veterinarians use: resting energy requirement times a factor for age and activity, converted into grams of your food.
Daily portion
–g / day
An individual pet's needs can differ by as much as 30%. Weigh your dog every 2–4 weeks and adjust the portion by 10% if the weight goes up or down. Count treats in the daily total (no more than about 10% of calories).
How the calculator works
First we calculate the resting energy requirement (RER): 70 × body weight in kg to the power of 0.75. That is the energy a dog needs lying down at rest. Then we multiply it by a factor:
- puppy up to 4 months: 3.0 × RER,
- puppy from 4 months to adulthood: 2.0 × RER,
- neutered adult: 1.6 × RER, intact adult: 1.8 × RER,
- inactive or prone to weight gain: 1.4 × RER,
- weight loss: 1.0 × RER for the target weight.
Finally we divide the calories by the energy density of the food to get grams. The factors for sporting and working dogs (2 to 3 × RER) are rough: their needs vary a lot.
Frequently asked questions
How much should I feed my dog a day?
It depends on weight, age, neutering, activity and the calorie content of the food. For example, a neutered adult dog weighing 15 kg (33 lb) needs about 850 kcal a day, which is roughly 230 g of dry food at 370 kcal per 100 g. Enter your dog's details in the calculator for a more precise result.
Is the feeding chart on the bag accurate?
The manufacturer's chart is a starting point for an average dog. Many dogs, especially neutered and less active ones, need less. The best guide is your dog's body condition: ribs you can feel under a thin layer of fat and a visible waist.
How many times a day should I feed my dog?
Adult dogs usually eat 2 meals a day. Puppies up to about 4 months eat 3 to 4 meals, then 2 to 3. Large breeds prone to bloat (gastric torsion) do better with 2 or 3 smaller portions than one big meal.
Where do I find the calories in my dog food?
Look on the bag for "metabolizable energy" in kcal/kg or kcal per cup or 100 g. In the US it is required on the label; in the EU it is optional, so if it is missing, ask the manufacturer. Without it the calculator assumes a typical 370 kcal per 100 g for dry food and 95 kcal per 100 g for wet food.
How much should I feed my dog to lose weight?
For weight loss, energy is calculated for the target weight, not the current one, using a factor of 1.0 × RER. Agree the target weight and the pace of loss with your veterinarian; losing weight too fast is harmful.
Sources
- 1Merck Veterinary Manual – Nutritional Requirements of Small Animalsmerckvetmanual.com
- 2Pet Nutrition Alliance – Calculating Calories Based on Pet Needs (MER/RER factors, PDF)petnutritionalliance.org
- 3dvm360 – Calculate the calories pets needdvm360.com
- 4Butterwick R. Calculating the energy content of pet food (Royal Canin Academy / Veterinary Focus)academy.royalcanin.com
- 5Lambert Vet Supply – Energy Requirements for Dogslambertvetsupply.com
- 6Regulation (EC) No 767/2009, Annex VII (labelling of compound feed for non-food producing animals)legislation.gov.uk
Results are estimates and do not replace advice from a veterinarian.
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