Determine the precise daily energy requirements for your feline friend.
Pounds (lbs)
Kilograms (kg)
Adult (Neutered/Spayed)
Adult (Intact/Unneutered)
Inactive / Obese Prone
Weight Loss Plan
Weight Gain Plan
Kitten (0-4 months)
Kitten (4-12 months)
Gestation (Pregnant)
Lactation (Nursing)
Senior Cat
0 kcal
Target Daily Calorie Intake
Understanding Your Cat's Calorie Needs
Feeding your cat the right amount of food is crucial for preventing obesity—the most common nutritional disorder in domestic felines. Just like humans, a cat's caloric needs are determined by their metabolic rate, activity level, and life stage.
How the Calculation Works
This calculator uses the Resting Energy Requirement (RER) formula, which is the energy used by a mammal at rest in a thermoneutral environment. The standard scientific formula used by veterinarians is:
RER = 70 × (Body Weight in kg)^0.75
Once the RER is established, we apply a multiplier based on your cat's specific lifestyle (Maintenance Energy Requirement or MER). For example, a growing kitten requires significantly more energy per pound than an inactive senior cat.
Realistic Examples
The Typical House Cat: A 10 lb (4.5 kg) neutered adult cat requires approximately 218 calories per day to maintain weight.
The Active Kitten: A 5 lb (2.3 kg) kitten under 4 months old requires about 275 calories per day due to the massive energy needed for growth.
The Weight Management Case: A 15 lb (6.8 kg) cat prone to obesity may only need about 245 calories to safely reach a healthier weight.
Important Factors for Feline Nutrition
Wet vs. Dry Food: Wet food generally has lower caloric density (fewer calories per gram) compared to dry kibble because of the high water content.
Treats Count: Treats should never exceed 10% of your cat's total daily caloric intake. If you give treats, you must reduce their main meal portions accordingly.
Consult Your Vet: While this calculator provides a scientifically-backed estimate, every cat is unique. Always consult with your veterinarian before starting a strict weight loss diet.
function calculateCatCalories() {
var weight = parseFloat(document.getElementById('catWeight').value);
var unit = document.getElementById('weightUnit').value;
var multiplier = parseFloat(document.getElementById('catStatus').value);
var resultBox = document.getElementById('catResultBox');
var calorieDisplay = document.getElementById('calorieDisplay');
var rerExplanation = document.getElementById('rerExplanation');
if (isNaN(weight) || weight <= 0) {
alert("Please enter a valid weight for your cat.");
return;
}
// Convert weight to kg for the formula
var weightInKg = weight;
if (unit === 'lb') {
weightInKg = weight * 0.453592;
}
// Calculate RER (Resting Energy Requirement)
// Formula: 70 * (weight_kg ^ 0.75)
var rer = 70 * Math.pow(weightInKg, 0.75);
// Calculate Total Calories (MER)
var totalCalories = rer * multiplier;
// Update Display
calorieDisplay.innerHTML = Math.round(totalCalories) + " kcal / day";
rerExplanation.innerHTML = "Based on an RER of " + Math.round(rer) + " kcal and a lifestyle multiplier of " + multiplier + "x.";
resultBox.style.display = "block";
resultBox.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}