Home › Calorie Requirements Calculator
🍽️

Calorie Requirements Calculator

Calculate Resting Energy Requirement (RER) and Maintenance Energy Requirement (MER) for dogs and cats

Cat eating from a bowl
Advertisement
💡

Understanding RER vs MER

Resting Energy Requirement (RER) is the energy needed for basic body functions at rest in a thermoneutral environment. It's calculated using body weight and represents the minimum energy needed to sustain life.

Maintenance Energy Requirement (MER) is the total daily calories needed, accounting for activity level, life stage, and other factors. MER = RER × Life Stage Factor.

⚠️ Important: These calculations are starting point estimates. Individual pets may need 25-50% more or less depending on metabolism, activity, environment, and health status. Monitor body weight and body condition score every 2-4 weeks and adjust intake accordingly. For weight loss programs, consult with a veterinarian.

📚 References & Formulas

  1. Primary Formula - RER: 70 × (Body Weight in kg)0.75 = kcal/day
    This formula is accurate for all sizes and is the preferred method.
  2. Alternate Formula (2-45 kg patients): 30 × (Body Weight in kg) + 70 = kcal/day
    Less accurate for very small (<2 kg) or very large (>45 kg) patients.
  3. WSAVA Global Nutrition Committee. Nutritional Assessment Guidelines. Link
  4. Pet Nutrition Alliance. Calorie Calculator Methodology. Link
  5. Association for Pet Obesity Prevention. Veterinary DER Calculator. Link
  6. Hand MS, Thatcher CD, et al. Small Animal Clinical Nutrition, 5th edition. Mark Morris Institute, 2010.
  7. MER Multipliers are based on consensus recommendations from WSAVA, AAHA, and veterinary nutrition textbooks. Individual variation of ±50% is expected.