Calculate your estimated daily calorie needs for weight loss.
Male
Female
Sedentary (little to 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)
0.25 kg per week (slow & steady)
0.5 kg per week (recommended)
0.75 kg per week (faster)
1 kg per week (aggressive)
Understanding Your Calorie Needs for Weight Loss
Losing weight effectively and sustainably hinges on creating a calorie deficit – consuming fewer calories than your body burns. This calculator helps you estimate the daily calorie intake required to achieve your desired weekly weight loss.
Basal Metabolic Rate (BMR)
Your BMR is the number of calories your body burns at rest to maintain basic functions like breathing, circulation, and cell production. We use the Mifflin-St Jeor Equation, considered one of the most accurate:
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 TDEE is your BMR multiplied by an activity factor. This represents the total calories you burn in a day, including all physical 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
Creating a Calorie Deficit for Weight Loss
To lose weight, you need to consume fewer calories than your TDEE. A deficit of 3500 calories generally leads to approximately 0.5 kg (1 pound) of fat loss. This calculator translates your desired weekly weight loss into a daily calorie deficit:
1 kg of fat is roughly equivalent to 7700 calories.
1. Enter your current weight, height, age, and gender. These are crucial for calculating your BMR.
2. Select your activity level. Be honest to get the most accurate TDEE estimate.
3. Choose your desired weekly weight loss rate. A sustainable rate of 0.5 kg per week is generally recommended.
4. Click "Calculate My Calories" to see your estimated daily calorie target for weight loss.
Important Considerations:
This is an estimate. Individual metabolisms can vary.
Consult a healthcare professional or registered dietitian before making significant dietary changes.
Ensure your target calorie intake is not too low (generally not below 1200 for women or 1500 for men) to maintain adequate nutrient intake.
Combine a healthy diet with regular physical activity for optimal results.
function calculateCalories() {
var weight = parseFloat(document.getElementById("weight").value);
var height = parseFloat(document.getElementById("height").value);
var age = parseFloat(document.getElementById("age").value);
var gender = document.getElementById("gender").value;
var activityLevel = document.getElementById("activityLevel").value;
var weightLossGoal = parseFloat(document.getElementById("weightLossGoal").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = "; // Clear previous results
// Input validation
if (isNaN(weight) || isNaN(height) || isNaN(age) || weight <= 0 || height <= 0 || age <= 0) {
resultDiv.innerHTML = 'Error: Please enter valid positive numbers for weight, height, and age.';
return;
}
// Calculate BMR (Mifflin-St Jeor Equation)
var bmr;
if (gender === "male") {
bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5;
} else { // female
bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161;
}
// Calculate TDEE
var activityMultiplier;
switch (activityLevel) {
case "sedentary":
activityMultiplier = 1.2;
break;
case "light":
activityMultiplier = 1.375;
break;
case "moderate":
activityMultiplier = 1.55;
break;
case "very":
activityMultiplier = 1.725;
break;
case "extra":
activityMultiplier = 1.9;
break;
default:
activityMultiplier = 1.375; // Default to lightly active
}
var tdee = bmr * activityMultiplier;
// Calculate calorie deficit for weight loss
var caloriesPerKg = 7700; // Approximate calories in 1 kg of fat
var weeklyCalorieDeficit = weightLossGoal * caloriesPerKg;
var dailyCalorieDeficit = weeklyCalorieDeficit / 7;
// Calculate target daily calorie intake
var targetDailyCalories = tdee – dailyCalorieDeficit;
// Ensure target calories are not dangerously low
var minCaloriesForMen = 1500;
var minCaloriesForWomen = 1200;
var finalTargetCalories = targetDailyCalories;
if (gender === "male" && finalTargetCalories < minCaloriesForMen) {
finalTargetCalories = minCaloriesForMen;
resultDiv.innerHTML += 'Warning: Your calculated target calories are below the recommended minimum for men. Setting to ' + minCaloriesForMen + ' kcal/day. Consult a professional for very low-calorie diets.';
} else if (gender === "female" && finalTargetCalories < minCaloriesForWomen) {
finalTargetCalories = minCaloriesForWomen;
resultDiv.innerHTML += 'Warning: Your calculated target calories are below the recommended minimum for women. Setting to ' + minCaloriesForWomen + ' kcal/day. Consult a professional for very low-calorie diets.';
}
// Display results
resultDiv.innerHTML = `
Your Estimated Calorie Needs
Your Basal Metabolic Rate (BMR) is approximately ${bmr.toFixed(0)} kcal/day.
Your Total Daily Energy Expenditure (TDEE) is approximately ${tdee.toFixed(0)} kcal/day.
To lose ${weightLossGoal} kg per week, you need a daily deficit of approximately ${dailyCalorieDeficit.toFixed(0)} kcal/day.
Your Target Daily Calorie Intake: ${finalTargetCalories.toFixed(0)} kcal/day
This is an estimate. Adjust based on your progress and consult a health professional.
`;
}