Dog Resting Energy Requirement Calculator
The resting energy requirement (RER) is the foundational calculation in canine nutrition, representing the calories a dog needs at complete rest. The widely accepted veterinary formula, endorsed by AAHA and used in standard veterinary clinical nutrition, is RER (kcal/day) = 70 multiplied by body weight in kilograms raised to the 0.75 power. This allometric scaling, derived from Kleiber's law of metabolic scaling, accurately reflects how metabolic rate relates to body size across all dog breeds, from Chihuahuas to Great Danes. To find the actual daily energy requirement, multiply RER by the appropriate life stage factor. This calculator also provides daily energy estimates at common life stage multipliers.
Dog RER formula
RER (kcal/day) = 70 x (Body weight in kg)^0.75
To convert from pounds to kg: Weight (kg) = Weight (lb) / 2.2046. The RER is then multiplied by a life stage factor to get the daily energy requirement (DER). AAHA life stage multipliers: neutered adult 1.6, intact adult 1.8, weight loss 1.0, weight gain 1.7-2.0, puppy under 4 months 3.0, puppy over 4 months 2.0.
Applying RER to practical feeding
- Determine the calorie content of your dog's food in kcal per cup or per kg from the manufacturer's guaranteed analysis or feeding trials data.
- Divide the target daily kcal by the food's kcal/cup to find the daily feeding amount.
- Monitor body weight and body condition score every 2-4 weeks and adjust the feeding amount accordingly.
- Treats should not exceed 10% of total daily caloric intake to avoid unbalancing the complete diet.
- Senior dogs, dogs with endocrine diseases (hypothyroidism, Cushing's), and dogs post-desexing often have lower energy requirements than the standard multipliers suggest.
Dog resting energy calculator: frequently asked questions
What is the resting energy requirement (RER) for dogs?
RER is the energy a dog needs at complete rest to maintain basic physiological functions including respiration, circulation, and temperature regulation. The standard AAHA/veterinary formula is RER (kcal/day) = 70 x (body weight in kg)^0.75. It is the starting point for calculating total daily caloric needs.
How do I calculate total daily energy from RER?
Multiply the RER by a life stage or activity factor. Common multipliers: neutered adult dog 1.6 x RER; intact adult dog 1.8 x RER; weight loss 1.0 x RER; weight gain 1.7-2.0 x RER; working dogs 2-8 x RER depending on activity. These factors are from AAHA and veterinary clinical guidelines.
Why does the formula use body weight to the power of 0.75?
Metabolic rate scales with body mass to the 0.75 power (Kleiber's law), not linearly. A 40 kg dog does not need exactly 4 times the energy of a 10 kg dog; the relationship is allometric. The exponent 0.75 is established from physiological research across species.
Should I use ideal weight or current weight for RER?
For weight loss programs, use the dog's ideal (target) body weight rather than current weight to calculate the target calorie intake. For maintenance, current weight is used. Your veterinarian will advise on the appropriate target weight based on the dog's body condition score.
Is the formula 70 x kg^0.75 different from 30 x kg + 70?
The linear formula (30 x kg + 70) is a simplified approximation sometimes used for dogs between 2 and 45 kg. The allometric formula (70 x kg^0.75) is more accurate across all body weights and is the preferred standard in current veterinary nutrition guidelines.
Official sources
- American Animal Hospital Association (AAHA) Nutritional Assessment Guidelines: AAHA Homepage.
- USDA National Agricultural Library, Animal Nutrition: NAL Homepage.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.