How Dog Food Portions Are Calculated
This calculator uses the Resting Energy Requirement (RER) formula recommended by veterinary nutritionists. RER represents the minimum energy (in kilocalories) a dog needs each day to sustain basic biological functions — breathing, circulation, and cell repair — while at complete rest.
Because dogs have very different metabolic needs depending on their life stage and activity level, the RER is multiplied by adjustment factors to arrive at a realistic daily calorie target. A working sled dog, for example, may need more than twice the calories of an inactive senior dog of the same weight.
The RER Formula
- RER (kcal/day) = 70 × (body weight in kg)^0.75
- Daily Calories = RER × life stage factor × activity factor
- Cups per day = Daily Calories ÷ food caloric density (default: 350 kcal/cup)
Life Stage and Activity Factors
The life stage factor accounts for the dramatic difference in energy needs across a dog's life. Young puppies need up to three times more calories per kilogram than a senior dog. Neutered adults have slightly lower needs than intact adults because of hormonal differences in metabolism. The activity factor then adjusts for how much exercise the dog gets each day.
How to Use the Results
The calorie and cup estimates are starting points. Every commercial food has a different caloric density — the kcal/cup figure is printed on the bag and varies widely (typically 280–500 kcal/cup for dry kibble). Enter your food's exact kcal/cup value to get a more accurate portion size.
- Weigh your dog regularly and adjust portions if weight changes
- Puppies and pregnant or nursing dogs have significantly higher needs
- Senior dogs often benefit from reduced portions to prevent weight gain
- Treats count toward daily calorie intake — factor them in
Frequently Asked Questions
How many cups of food should I feed my dog per day?
This depends entirely on your dog's weight, life stage, activity level, and the caloric density of the specific food you use. A 10kg neutered adult with moderate activity needs roughly 560–650 kcal/day, which equates to about 1.6–1.9 cups of average dry kibble (350 kcal/cup). Always check your food bag and consult your vet.
Should I feed my dog twice or three times a day?
Most adult dogs do well with two meals per day, which helps regulate blood sugar and reduces the risk of bloat in large breeds. Puppies generally need three or more smaller meals. Senior dogs and dogs prone to digestive issues may also benefit from more frequent, smaller portions.
Why is the RER formula used instead of simple weight-based guidelines?
Simple weight-based guidelines (like "1 cup per 10kg") ignore metabolic body size and life stage entirely. The RER formula, which raises body weight to the power of 0.75, accounts for the fact that larger animals have a lower metabolic rate per kilogram than smaller ones. This provides a much more accurate starting point.