Estimate your daily calorie needs based on the Mayo Clinic method.
Male
Female
Sedentary (little or no exercise)
Lightly active (light exercise/sports 1-3 days/week)
Moderately active (moderate exercise/sports 3-5 days/week)
Very active (hard exercise/sports 6-7 days a week)
Extra active (very hard exercise/sports & physical job)
Your Estimated Daily Calorie Needs:
— kcal
Understanding Your Daily Calorie Needs
Determining your daily calorie needs is a fundamental step towards managing your weight, whether your goal is to lose, maintain, or gain. The Mayo Clinic, a renowned medical institution, advocates for a personalized approach to calorie counting, emphasizing that individual needs vary significantly based on several factors. This calculator uses the Mifflin-St Jeor equation, which is widely recognized for its accuracy in estimating Basal Metabolic Rate (BMR) – the number of calories your body burns at rest.
How the Calculation Works (Mifflin-St Jeor Equation)
The calculation involves two main steps:
Calculating Basal Metabolic Rate (BMR): This is the energy your body needs to perform basic life-sustaining functions like breathing, circulation, and cell production.
For Men: BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) + 5
For Women: BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) – 161
Adjusting for Activity Level: Your BMR is then multiplied by an activity factor to estimate your Total Daily Energy Expenditure (TDEE) – the total number of calories you burn in a day.
Sedentary: BMR x 1.2 (little or no exercise)
Lightly active: BMR x 1.375 (light exercise/sports 1-3 days/week)
Moderately active: BMR x 1.55 (moderate exercise/sports 3-5 days/week)
Very active: BMR x 1.725 (hard exercise/sports 6-7 days a week)
Extra active: BMR x 1.9 (very hard exercise/sports & physical job)
Factors Influencing Calorie Needs
The calculator takes into account the primary factors that affect calorie requirements:
Age: Metabolism tends to slow down with age.
Gender: Men generally have more muscle mass and a higher BMR than women.
Weight and Height: These determine Body Mass Index (BMI) and influence the energy needed to maintain body functions.
Activity Level: This is a crucial factor, as physical activity significantly increases calorie expenditure.
Disclaimer
This calculator provides an estimate based on standard formulas. Individual metabolic rates can vary. For personalized dietary advice and specific weight management plans, it is always recommended to consult with a healthcare professional or a registered dietitian.
function calculateCalories() {
var age = document.getElementById("age").value;
var gender = document.getElementById("gender").value;
var weightKg = document.getElementById("weightKg").value;
var heightCm = document.getElementById("heightCm").value;
var activityLevel = document.getElementById("activityLevel").value;
var calorieResultElement = document.getElementById("calorieResult");
// Input validation
if (age === "" || weightKg === "" || heightCm === "" || isNaN(age) || isNaN(weightKg) || isNaN(heightCm) || age <= 0 || weightKg <= 0 || heightCm <= 0) {
calorieResultElement.textContent = "Please enter valid positive numbers for age, weight, and height.";
calorieResultElement.style.color = "#dc3545"; // Red for error
return;
}
var bmr = 0;
var activityMultiplier = parseFloat(activityLevel);
// Calculate BMR using Mifflin-St Jeor equation
if (gender === "male") {
bmr = (10 * parseFloat(weightKg)) + (6.25 * parseFloat(heightCm)) – (5 * parseFloat(age)) + 5;
} else { // female
bmr = (10 * parseFloat(weightKg)) + (6.25 * parseFloat(heightCm)) – (5 * parseFloat(age)) – 161;
}
// Calculate Total Daily Energy Expenditure (TDEE)
var tdee = bmr * activityMultiplier;
// Display the result
calorieResultElement.textContent = Math.round(tdee);
calorieResultElement.style.color = "#28a745"; // Green for success
}