Estimate your daily caloric needs for weight maintenance, loss, or gain.
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)
Estimated Daily Caloric Needs:
— kcal
Understanding Calorie Counting and Your Daily Needs
Calorie counting is a fundamental aspect of understanding your body's energy balance. A calorie is a unit of energy. The food and drinks we consume provide our bodies with energy in the form of calories, which are used to fuel all our bodily functions, from breathing and thinking to physical activity.
The Basal Metabolic Rate (BMR)
The cornerstone of calorie calculations is the Basal Metabolic Rate (BMR). This is the number of calories your body needs to perform essential life-sustaining activities at rest. These include breathing, circulation, cell production, and hormone regulation. It's the energy your body would burn if you were to rest all day.
The Mifflin-St Jeor Equation
One of the most widely accepted and accurate formulas for calculating BMR is the Mifflin-St Jeor equation. It's generally considered more reliable than older formulas like Harris-Benedict. The formulas are:
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 represents the calories you burn at rest. However, most people are not at rest all day. To get a more accurate picture of your daily calorie needs, you need to account for your physical activity level. This is calculated by multiplying your BMR by an activity factor, resulting in your Total Daily Energy Expenditure (TDEE).
The activity factors used in this calculator are common estimates:
Very Active: BMR × 1.725 (hard exercise/sports 6-7 days a week)
Extra Active: BMR × 1.9 (very hard exercise/sports & physical job or 2x training)
The formula for TDEE is:
TDEE = BMR × Activity Factor
Using This Calculator
This calculator uses the Mifflin-St Jeor equation to determine your BMR and then applies your chosen activity level to estimate your TDEE. This TDEE is the number of calories you need to consume daily to maintain your current weight.
To Lose Weight: Consume fewer calories than your TDEE (a deficit of 500-1000 calories per day typically leads to 1-2 pounds of weight loss per week).
To Gain Weight: Consume more calories than your TDEE (a surplus of 500-1000 calories per day typically leads to 1-2 pounds of weight gain per week).
To Maintain Weight: Consume approximately the number of calories indicated by your TDEE.
Disclaimer: This calculator provides an estimate. Individual metabolic rates can vary. For personalized dietary advice, please consult a healthcare professional or a registered dietitian.
function calculateCalories() {
var age = parseFloat(document.getElementById("age").value);
var gender = document.getElementById("gender").value;
var weight = parseFloat(document.getElementById("weight").value);
var height = parseFloat(document.getElementById("height").value);
var activityLevel = parseFloat(document.getElementById("activityLevel").value);
var resultValueElement = document.getElementById("result-value");
if (isNaN(age) || isNaN(weight) || isNaN(height) || isNaN(activityLevel) || age <= 0 || weight <= 0 || height <= 0) {
resultValueElement.innerText = "Invalid input";
return;
}
var bmr = 0;
if (gender === "male") {
bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5;
} else { // female
bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161;
}
var tdee = bmr * activityLevel;
// Round to the nearest whole number for a cleaner display
var roundedTdee = Math.round(tdee);
resultValueElement.innerText = roundedTdee + " kcal";
}