Calculate your estimated daily caloric needs using the Mifflin-St Jeor equation.
Male
Female
Sedentary (little or no exercise)
Lightly active (exercise 1-3 days/week)
Moderately active (exercise 3-5 days/week)
Very active (exercise 6-7 days/week)
Extra active (very intense exercise & physical job)
0 kcal (Estimate)
Understanding and Calculating Your Daily KCal Needs
Understanding your daily caloric needs, often referred to as KCal (kilocalories), is fundamental for managing your weight, optimizing athletic performance, or simply maintaining overall health. Your body requires a certain amount of energy from food to perform basic life functions (basal metabolic rate) and to support your daily activities. The calculation for your daily KCal needs typically involves estimating your Basal Metabolic Rate (BMR) and then adjusting it based on your activity level.
The Mifflin-St Jeor Equation
The Mifflin-St Jeor equation is widely considered one of the most accurate formulas for estimating BMR. It takes into account your gender, weight, height, and age.
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)
Once you have your BMR, you multiply it by an activity factor to estimate your Total Daily Energy Expenditure (TDEE), which represents your total daily calorie needs.
TDEE = BMR × Activity Factor
The activity factors used in this calculator are standard estimates:
1.2: Sedentary (little or no exercise) – Desk job, minimal daily movement.
1.375: Lightly active (exercise 1-3 days/week) – Light exercise or sports 1-3 days a week.
1.55: Moderately active (exercise 3-5 days/week) – Moderate exercise or sports 3-5 days a week.
1.725: Very active (exercise 6-7 days/week) – Hard exercise or sports 6-7 days a week.
1.9: Extra active (very intense exercise & physical job) – Very hard exercise, physical job, or training for endurance events.
How to Use This Calculator
Simply enter your gender, current weight in kilograms, height in centimeters, age in years, and select your typical weekly activity level. The calculator will then provide an estimate of your daily KCal needs to maintain your current weight.
Important Considerations:
This is an estimate. Individual metabolisms can vary.
For weight loss, you typically need to consume fewer calories than your TDEE.
For weight gain, you typically need to consume more calories than your TDEE.
Consult with a healthcare professional or a registered dietitian for personalized advice, especially if you have underlying health conditions.
function calculateKcals() {
var gender = document.getElementById("gender").value;
var weight = parseFloat(document.getElementById("weight").value);
var height = parseFloat(document.getElementById("height").value);
var age = parseFloat(document.getElementById("age").value);
var activityLevel = parseFloat(document.getElementById("activityLevel").value);
var bmr = 0;
// Validate inputs
if (isNaN(weight) || isNaN(height) || isNaN(age) || weight <= 0 || height <= 0 || age <= 0) {
document.getElementById("result").innerHTML = "Invalid input. Please enter valid numbers.";
return;
}
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;
// Display the result
document.getElementById("result").innerHTML = Math.round(tdee) + " kcal (Estimate)";
}