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 caloric needs will appear here.
Understanding Your Daily Caloric Needs
Determining your daily caloric needs is a fundamental aspect of managing your health, whether your goal is weight loss, weight gain, or maintenance. This calculator uses the Mifflin-St Jeor equation, widely considered one of the most accurate formulas for estimating Basal Metabolic Rate (BMR), and then adjusts it for your activity level.
Basal Metabolic Rate (BMR)
Your BMR is the number of calories your body burns at rest to maintain basic life functions like breathing, circulation, and cell production. It's the minimum energy your body requires to function. The Mifflin-St Jeor equation is calculated as follows:
For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
Total Daily Energy Expenditure (TDEE)
Your BMR is then multiplied by an activity factor to estimate your Total Daily Energy Expenditure (TDEE), which represents the total number of calories you burn in a day, including all activities.
Sedentary: BMR × 1.2
Lightly Active: BMR × 1.375
Moderately Active: BMR × 1.55
Very Active: BMR × 1.725
Extra Active: BMR × 1.9
How to Use This Calculator
Simply enter your age, gender, weight in kilograms, height in centimeters, and select your typical weekly activity level. The calculator will provide an estimate of your daily caloric needs.
Important Considerations:
This calculator provides an estimate. Individual metabolic rates can vary.
For precise nutritional guidance, consult with a registered dietitian or healthcare professional.
Caloric needs change based on goals (weight loss, gain, maintenance), health conditions, and specific exercise routines.
function calculateCalories() {
var age = document.getElementById("age").value;
var gender = document.getElementById("gender").value;
var weight = document.getElementById("weight").value;
var height = document.getElementById("height").value;
var activityLevel = document.getElementById("activityLevel").value;
var resultDiv = document.getElementById("result");
// Input validation
if (age === "" || weight === "" || height === "" || isNaN(age) || isNaN(weight) || isNaN(height) || age <= 0 || weight <= 0 || height <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for Age, Weight, and Height.";
return;
}
var ageNum = parseFloat(age);
var weightNum = parseFloat(weight);
var heightNum = parseFloat(height);
var bmr;
// Calculate BMR using Mifflin-St Jeor equation
if (gender === "male") {
bmr = (10 * weightNum) + (6.25 * heightNum) – (5 * ageNum) + 5;
} else { // female
bmr = (10 * weightNum) + (6.25 * heightNum) – (5 * ageNum) – 161;
}
var activityMultiplier;
switch (activityLevel) {
case "sedentary":
activityMultiplier = 1.2;
break;
case "lightlyActive":
activityMultiplier = 1.375;
break;
case "moderatelyActive":
activityMultiplier = 1.55;
break;
case "veryActive":
activityMultiplier = 1.725;
break;
case "extraActive":
activityMultiplier = 1.9;
break;
default:
activityMultiplier = 1.2; // Default to sedentary if somehow not set
}
var tdee = bmr * activityMultiplier;
resultDiv.innerHTML = "Your estimated daily caloric needs are: " + tdee.toFixed(0) + " kcal";
}