Low (e.g., senior, couch potato)
Medium (e.g., average adult)
High (e.g., working dog, very active)
Understanding Your Pet's Nutritional Needs
Ensuring your pet receives the right amount of food is crucial for their health, energy levels, and longevity. This calculator helps you estimate the daily caloric intake your pet needs and, consequently, the amount of specific pet food to provide, based on their weight, species, activity level, and the caloric density of their food.
How the Calculation Works
The calculation is based on established veterinary guidelines and uses a few key factors:
Resting Energy Requirement (RER): This is the energy your pet needs at rest. It's calculated using their body weight. The formula is:
RER (kcal/day) = 70 * (Body Weight in kg ^ 0.75)
Maintenance Energy Requirement (MER): This is the total energy your pet needs daily to maintain their current body condition, factoring in their lifestyle and species. It's calculated by multiplying the RER by a factor determined by the pet's species and activity level.
General MER Factors:
Dogs:
Neutered/Spayed Adult: 1.6 x RER
Intact Adult: 1.8 x RER
Less Active/Senior: 1.2-1.4 x RER
Active/Working: 2.0-5.0 x RER
Cats:
Neutered/Spayed Adult: 1.2 x RER
Intact Adult: 1.4 x RER
Less Active/Indoor: 1.0-1.2 x RER
Active/Outdoor: 1.3-1.6 x RER
For simplicity in this calculator, we use generalized factors for activity levels:
Low Activity: ~1.2 x RER
Medium Activity: ~1.6 x RER (dogs) / ~1.3 x RER (cats)
High Activity: ~2.0 x RER (dogs) / ~1.5 x RER (cats)
Daily Food Amount: Once the MER is determined, we calculate how many grams of food are needed to meet that caloric requirement.
Daily Food (grams) = (MER (kcal/day) / Food Calories (kcal/100g)) * 100
Why Use This Calculator?
Prevent Obesity or Underweight Issues: Calorie management is key to maintaining a healthy weight.
Optimize Energy Levels: Ensure your pet has enough fuel for play, training, and daily activities.
Cost-Effective Feeding: Understand how much food you'll go through, aiding in budget planning.
Adapt to Different Foods: Easily compare how much of different brands or types of food to feed, as caloric density varies significantly.
Important Considerations:
This calculator provides an estimate. Individual pets may have unique metabolic rates or health conditions.
Consult your veterinarian for personalized dietary recommendations, especially for pets with medical issues (e.g., kidney disease, diabetes, allergies) or during specific life stages (e.g., pregnancy, lactation, growth).
Always monitor your pet's body condition and adjust food intake as needed.
Fresh water should always be available.
function calculateFoodAmount() {
var petType = document.getElementById("petType").value;
var petWeightKg = parseFloat(document.getElementById("petWeightKg").value);
var activityLevel = document.getElementById("activityLevel").value;
var foodKcalPer100g = parseFloat(document.getElementById("foodKcalPer100g").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
// Input validation
if (isNaN(petWeightKg) || petWeightKg <= 0) {
resultDiv.innerHTML = "Please enter a valid pet weight (kg).";
return;
}
if (isNaN(foodKcalPer100g) || foodKcalPer100g <= 0) {
resultDiv.innerHTML = "Please enter a valid calorie count for the food (kcal/100g).";
return;
}
// 1. Calculate Resting Energy Requirement (RER)
var rer = 70 * Math.pow(petWeightKg, 0.75);
// 2. Determine Maintenance Energy Requirement (MER) based on pet type and activity
var merFactor;
if (petType === "dog") {
if (activityLevel === "low") {
merFactor = 1.3; // Adjusted for general "low"
} else if (activityLevel === "medium") {
merFactor = 1.6;
} else { // high
merFactor = 2.0; // Adjusted for general "high"
}
} else { // cat
if (activityLevel === "low") {
merFactor = 1.1; // Adjusted for general "low"
} else if (activityLevel === "medium") {
merFactor = 1.3;
} else { // high
merFactor = 1.5; // Adjusted for general "high"
}
}
var mer = rer * merFactor;
// 3. Calculate Daily Food Amount in grams
var dailyFoodGrams = (mer / foodKcalPer100g) * 100;
// Display the result
resultDiv.innerHTML =
dailyFoodGrams.toFixed(2) + " grams" +
"Per day";
}