Dog Food Calculator: RER & DER Calorie Calculator
Wondering how much to feed your dog? This free dog nutrition calculator estimates your dog's daily calorie needs using Resting Energy Requirement (RER) and Daily Energy Requirement (DER), then converts that into portion sizes — the same veterinary nutrition science behind every NouriPet meal plan.
How to calculate how much to feed your dog
Every accurate feeding calculation starts with two numbers: your dog's Resting Energy Requirement (RER) and Daily Energy Requirement (DER). RER is the baseline number of calories a dog burns at complete rest. DER takes that baseline and adjusts it for real life — activity, age and life stage, whether your dog is spayed or neutered, and current body condition.
The RER formula
Veterinary nutritionists calculate RER with the allometric formula:
RER = 70 × (body weight in kg)0.75
For example, a 50 lb dog weighs about 22.7 kg, giving an RER of roughly 728 kcal per day. To convert pounds to kilograms, divide by 2.2.
From RER to DER
Once you have RER, multiply it by an activity and life-stage factor to get DER — the number you actually feed to:
- • Low-activity / less active adult dogs: about 1.3–1.4 × RER
- • Typical neutered adult dogs (moderate activity): about 1.6 × RER
- • Very active or working dogs: about 1.8–2.0 × RER
- • Puppies (still growing): about 2.0–3.0 × RER
Body condition matters too: an overweight dog is fed toward the lower end (or below RER × 1.0 for weight loss under vet guidance), while an underweight or very picky eater may need more. Getting this number right is especially important for picky eaters and dogs with sensitive stomachs, where every calorie counts.
Dog calorie chart by weight (RER & DER)
Estimated daily calories for a healthy adult dog. RER is calories at rest; DER columns show daily needs by activity level. These are starting points — use the calculator below for a number tailored to your dog.
| Dog weight | RER (kcal/day) | DER — low activity | DER — moderate | DER — high activity |
|---|---|---|---|---|
| 10 lb | 218 | 294 | 348 | 413 |
| 20 lb | 366 | 494 | 585 | 695 |
| 30 lb | 496 | 670 | 794 | 942 |
| 40 lb | 615 | 831 | 985 | 1,169 |
| 50 lb | 727 | 982 | 1,164 | 1,382 |
| 70 lb | 936 | 1,264 | 1,498 | 1,779 |
| 90 lb | 1,131 | 1,526 | 1,809 | 2,148 |
Figures assume a healthy, neutered adult dog at an ideal body condition. Puppies, seniors, pregnant or nursing dogs, and dogs with medical conditions have different needs — always confirm with your veterinarian.
Educational Tools
These calculators are designed to help you understand how we determine your dog's nutritional needs. While they provide scientifically-based estimates, always consult with your veterinarian for specific dietary recommendations, especially if your dog has health conditions.
Dog food calculator: frequently asked questions
How much should I feed my dog?
Start from your dog's Daily Energy Requirement (DER) — the total calories they need each day. Divide those calories by the calorie density of their food to get the daily amount, then split it across meals. A 50 lb adult dog with moderate activity needs roughly 1,100–1,200 kcal per day. Use the calculator above to get a number tailored to your dog's weight, age, activity, and body condition.
What is RER (Resting Energy Requirement) for a dog?
RER is the number of calories a dog needs at rest, just to keep its body functioning. It's calculated with the formula RER = 70 × (body weight in kg)^0.75. RER is the foundation every other feeding calculation is built on.
What is the difference between RER and DER?
RER (Resting Energy Requirement) is calories needed at rest. DER (Daily Energy Requirement) is the real-world total once you account for activity, life stage, neuter status, and body condition. DER = RER × an activity/life-stage factor (roughly 1.3–1.4 for low-activity adults, 1.6 for moderate, up to 1.8–2.0 for very active dogs, and higher for puppies).
How do I calculate my dog's daily calories?
First calculate RER = 70 × (weight in kg)^0.75. Then multiply RER by the appropriate activity/life-stage factor to get DER. For example, a 22.7 kg (50 lb) neutered adult dog with moderate activity: RER ≈ 728 kcal, DER ≈ 728 × 1.6 ≈ 1,165 kcal per day. The calculator on this page does all of this for you.
Is this dog calorie calculator free?
Yes. The RER, DER, portion, and EPA/DHA calculators on this page are completely free to use. They're built on the same veterinary nutrition science and AAFCO guidelines we use to formulate NouriPet meal plans.
Ready for a personalized plan?
Our meal plan builder uses these same calculations to create a customized nutrition plan for your dog.