Estimate your daily calorie needs based on your personal details and activity level.
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 or 2x training)
Your Estimated Daily Calorie Needs:
— kcal
Understanding Your Calorie Needs
Calculating your daily calorie needs is a fundamental step towards managing your weight and ensuring your body receives adequate energy for its functions. This calculator uses the Mifflin-St Jeor equation, which is widely considered one of the most accurate methods for estimating Basal Metabolic Rate (BMR) and then adjusts it based on your activity level to determine your Total Daily Energy Expenditure (TDEE).
The Math Behind the Calculation
The process involves two main steps:
Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest to maintain basic functions like breathing, circulation, and cell production. The Mifflin-St Jeor equation is used:
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): This is your BMR multiplied by an activity factor that represents your average daily physical activity.
TDEE = BMR × Activity Factor
The activity factors used in this calculator are standard multipliers:
Sedentary: 1.2
Lightly active: 1.375
Moderately active: 1.55
Very active: 1.725
Extra active: 1.9
The result displayed is your estimated TDEE, which represents the total number of calories you should consume daily to maintain your current weight.
How to Use This Calculator
To get an accurate estimate, please provide the following information:
Age: Your current age in years.
Gender: Select 'Male' or 'Female'.
Weight: Your weight in kilograms (kg).
Height: Your height in centimeters (cm).
Activity Level: Choose the option that best describes your typical weekly physical activity. Be honest to get the most relevant results.
Clicking the "Calculate Daily Calories" button will provide your estimated daily calorie requirement to maintain your current weight. This figure can be a valuable starting point for weight management goals, whether it's to lose, gain, or maintain weight.
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 bmr = 0;
// Validate inputs
if (age === "" || weight === "" || height === "" || isNaN(age) || isNaN(weight) || isNaN(height) || age <= 0 || weight <= 0 || height <= 0) {
document.getElementById("calorieResult").innerHTML = "Invalid input. Please enter valid positive numbers.";
return;
}
// Calculate BMR using Mifflin-St Jeor Equation
if (gender === "male") {
bmr = (10 * parseFloat(weight)) + (6.25 * parseFloat(height)) – (5 * parseFloat(age)) + 5;
} else { // female
bmr = (10 * parseFloat(weight)) + (6.25 * parseFloat(height)) – (5 * parseFloat(age)) – 161;
}
// Calculate TDEE (Total Daily Energy Expenditure)
var tdee = bmr * parseFloat(activityLevel);
// Display the result
document.getElementById("calorieResult").innerHTML = Math.round(tdee) + " kcal";
}