Dog Daily Calorie Calculator
Knowing roughly how many calories your dog needs each day helps you feed the right amount and keep a healthy body condition. Veterinary nutrition estimates this in two steps: the Resting Energy Requirement (RER) from body weight, then a maintenance factor for life stage and activity. This calculator uses the standard allometric equation RER = 70 times body weight in kilograms to the power of 0.75, then multiplies by an activity factor you set. Because the right factor depends on your individual dog, it is a user-editable input. Treat the result as a starting estimate and confirm with your veterinarian.
Dog calorie formula
RER = 70 * (body weight kg)^0.75 (kcal/day)
MER = RER * activity factor (kcal/day)
(kcal = the Calories on pet-food labels)
Energy scales with metabolic body size (weight^0.75), so small dogs need more calories per kilogram than large dogs. The activity factor is editable for your dog's life stage and activity.
Typical activity factors
- Weight loss: about 1.0; inactive or weight-gain: about 1.2 to 1.4.
- Neutered adult, normal activity: about 1.6.
- Intact adult, normal activity: about 1.8.
- Working dogs: about 2.0 to 5.0 depending on workload.
- Puppies: about 2.0 to 3.0 depending on age.
Dog calorie needs: frequently asked questions
How are a dog's daily calories estimated?
Veterinary nutrition uses a two-step method. First, the Resting Energy Requirement (RER) is RER = 70 * (body weight in kg)^0.75, the calories a resting animal needs. Then the daily Maintenance Energy Requirement (MER) is RER multiplied by a life-stage and activity factor. The result is in kilocalories (the Calories on pet-food labels) per day.
What activity factor should I use?
Common factors are around 1.6 for a neutered adult dog at normal activity, 1.8 for an intact adult, 1.0 for weight loss, 1.2 to 1.4 for weight-gain or inactive dogs, 2.0 to 5.0 for working dogs, and 2.0 to 3.0 for puppies depending on age. These multipliers are guidelines, so the factor is a user-editable input; adjust it for your dog and confirm with your veterinarian.
Why use body weight to the power of 0.75?
Energy use does not scale linearly with body mass; it scales with metabolic body size, which is body weight raised to roughly the 0.75 power (metabolic scaling). This means a small dog needs more calories per kilogram than a large dog. The 70 coefficient and 0.75 exponent are the standard allometric RER equation used across pet-weight ranges.
Is there a simpler linear RER estimate?
Yes. For dogs between about 2 and 45 kg a linear approximation RER = 30 * body weight in kg + 70 is sometimes used, but the exponential 70 * weight^0.75 formula is accurate across all weights and is the one this calculator uses. The two agree closely in the mid weight range and diverge for very small or very large dogs.
Should I rely on this number alone?
No. Calculated needs are a starting point. Actual requirements vary with breed, body condition, environment, health and individual metabolism, and can differ from the estimate by a wide margin. Monitor your dog's body condition score and weight over time and adjust food accordingly, and consult your veterinarian for medical or weight-management diets.
Official sources
- American Animal Hospital Association: Clinical resources and nutrition guidelines.
- U.S. FDA: Animal and Veterinary.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. This tool is informational and is not veterinary advice. See our methodology.