Dog & Cat Food Calculator: Your Pet Feeding Guide
Calculate the right daily food portion for your dog based on weight, age, and activity level. Supports dry, wet, and mixed feeding for accurate portions.
Use CalculatorThe Metabolizable Energy Requirement (MER) for dogs is the personalized daily caloric need calculated from the dog's resting energy requirement multiplied by a life stage and lifestyle factor. Because dogs range from 1-lb Chihuahuas to 200-lb Mastiffs, have vastly different activity levels, and metabolic rates are significantly affected by neuter status, the bag feeding guide is rarely appropriate for any individual dog. The Dog MER Calculator generates a precise daily caloric target for your dog.
MER Formula for Dogs
Step 1: RER (kcal/day) = 70 x (body weight in kg)^0.75
For dogs under 2 kg or over 45 kg, a linear approximation is sometimes used: RER = 30 x (body weight in kg) + 70
| Dog Category | MER Multiplier | Example: 20 kg dog (RER ~394 kcal) |
|---|---|---|
| Neutered adult, ideal weight | 1.6 | 630 kcal/day |
| Intact adult | 1.8 | 709 kcal/day |
| Inactive/obese-prone adult | 1.2-1.4 | 473-552 kcal/day |
| Weight loss (use ideal body weight in RER) | 1.0 | Use ideal weight |
| Puppy 0-4 months | 3.0 | 1,182 kcal/day (from RER of puppy weight) |
| Puppy 4 months to adult | 2.0 | 788 kcal/day |
| Light work | 2.0 | 788 kcal/day |
| Moderate work (active working dog) | 3.0 | 1,182 kcal/day |
| Heavy work (sled dog, field trials) | 4.0-8.0 | 1,576-3,152 kcal/day |
| Pregnant (last trimester) | 3.0 | 1,182 kcal/day |
| Lactating (peak: 3-5 weeks) | 4.0-8.0 | 1,576-3,152 kcal/day (free choice feeding recommended) |
Sample Daily Caloric Needs by Dog Size
Use the table below to compare Sample Daily Caloric Needs by Dog Size.
| Dog Weight | Neutered Adult | Active Adult | Senior (less active) |
|---|---|---|---|
| 5 lbs (2.3 kg) | 131 kcal | 164 kcal | 105 kcal |
| 10 lbs (4.5 kg) | 220 kcal | 275 kcal | 176 kcal |
| 20 lbs (9 kg) | 370 kcal | 463 kcal | 296 kcal |
| 30 lbs (13.6 kg) | 504 kcal | 630 kcal | 403 kcal |
| 50 lbs (22.7 kg) | 730 kcal | 913 kcal | 584 kcal |
| 75 lbs (34 kg) | 993 kcal | 1,241 kcal | 794 kcal |
| 100 lbs (45.4 kg) | 1,234 kcal | 1,543 kcal | 987 kcal |
Adjusting for Real-World Variability
MER calculations provide a starting point. Real-world metabolic rates vary by approximately plus or minus 25% from calculated values due to individual metabolic variation. Start at the calculated MER, feed consistently for 4-6 weeks, and adjust based on BCS assessment. If BCS increases, reduce by 10%. If BCS decreases and dog seems hungry, increase by 10%.
Frequently Asked Questions
Why does the bag recommendation seem much higher than my calculator result?
Pet food bag feeding guides are typically printed for intact adult dogs, which have higher caloric requirements than neutered dogs. They also tend to slightly overestimate to encourage product consumption. The calculated MER using the neutered multiplier (1.6) will almost always be below the bag recommendation for a typical neutered indoor adult dog.
My dog is losing weight on the calculated MER amount. What should I do?
Increase by 10% and reassess in 2-4 weeks. If weight loss continues despite increases, consult your veterinarian to rule out malabsorption, parasites, dental disease causing reduced food intake, metabolic disease, or incorrect calorie density on your food label.
Note: MER is a starting estimate. Portion needs can change with activity, age, body condition, and weight trend.
Helpful related calculators
Continue with Dog & Cat Food Calculator: Your Pet Feeding Guide, Dog Protein Calculator by Weight, Raw Dog Food Calculator for the next practical step.
