.calorie-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 700px;
margin: 20px auto;
padding: 25px;
border: 1px solid #e0e0e0;
border-radius: 10px;
background-color: #ffffff;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}
.calorie-calculator-container h2 {
text-align: center;
color: #333;
margin-bottom: 25px;
font-size: 28px;
font-weight: 600;
}
.calorie-calculator-container .input-group {
margin-bottom: 18px;
display: flex;
flex-direction: column;
}
.calorie-calculator-container label {
display: block;
margin-bottom: 8px;
color: #555;
font-weight: 500;
font-size: 15px;
}
.calorie-calculator-container input[type="number"],
.calorie-calculator-container select {
width: 100%;
padding: 12px;
border: 1px solid #ccc;
border-radius: 6px;
box-sizing: border-box;
font-size: 16px;
color: #333;
background-color: #fdfdfd;
transition: border-color 0.3s ease;
}
.calorie-calculator-container input[type="number"]:focus,
.calorie-calculator-container select:focus {
border-color: #007bff;
outline: none;
box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
}
.calorie-calculator-container button {
display: block;
width: 100%;
padding: 14px 20px;
background-color: #007bff;
color: white;
border: none;
border-radius: 6px;
font-size: 18px;
font-weight: 600;
cursor: pointer;
transition: background-color 0.3s ease, transform 0.2s ease;
margin-top: 25px;
}
.calorie-calculator-container button:hover {
background-color: #0056b3;
transform: translateY(-1px);
}
.calorie-calculator-container .result-container {
margin-top: 30px;
padding: 20px;
border: 1px solid #d4edda;
background-color: #e9f7ef;
border-radius: 8px;
text-align: center;
font-size: 18px;
color: #155724;
font-weight: 500;
line-height: 1.6;
}
.calorie-calculator-container .result-container strong {
color: #0a3622;
font-size: 22px;
display: block;
margin-top: 10px;
}
.calorie-calculator-container .error-message {
color: #dc3545;
margin-top: 10px;
text-align: center;
font-weight: 500;
}
.calorie-calculator-container .article-content {
margin-top: 40px;
padding-top: 20px;
border-top: 1px solid #eee;
color: #444;
line-height: 1.7;
font-size: 16px;
}
.calorie-calculator-container .article-content h3 {
color: #333;
font-size: 24px;
margin-bottom: 15px;
font-weight: 600;
}
.calorie-calculator-container .article-content p {
margin-bottom: 15px;
}
.calorie-calculator-container .article-content ul {
list-style-type: disc;
margin-left: 20px;
margin-bottom: 15px;
}
.calorie-calculator-container .article-content li {
margin-bottom: 8px;
}
function calculateCalories() {
var gender = document.getElementById("gender").value;
var age = parseFloat(document.getElementById("age").value);
var weight = parseFloat(document.getElementById("weight").value);
var height = parseFloat(document.getElementById("height").value);
var activityLevel = document.getElementById("activityLevel").value;
var goal = document.getElementById("goal").value;
var resultDiv = document.getElementById("calorieResult");
var errorDiv = document.getElementById("calorieError");
var dailyCaloriesSpan = document.getElementById("dailyCalories");
resultDiv.style.display = "none";
errorDiv.style.display = "none";
errorDiv.innerHTML = "";
if (isNaN(age) || isNaN(weight) || isNaN(height) || age <= 0 || weight <= 0 || height <= 0) {
errorDiv.innerHTML = "Please enter valid positive numbers for age, weight, and height.";
errorDiv.style.display = "block";
return;
}
var bmr;
// Mifflin-St Jeor Equation
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; // Total Daily Energy Expenditure
switch (activityLevel) {
case "sedentary":
tdee = bmr * 1.2;
break;
case "lightlyActive":
tdee = bmr * 1.375;
break;
case "moderatelyActive":
tdee = bmr * 1.55;
break;
case "veryActive":
tdee = bmr * 1.725;
break;
case "extraActive":
tdee = bmr * 1.9;
break;
default:
tdee = bmr * 1.2; // Default to sedentary if somehow not selected
}
var finalCalories = tdee;
switch (goal) {
case "maintain":
// No change, TDEE is the maintenance
break;
case "mildLoss":
finalCalories -= 250; // ~0.25 kg/week loss
break;
case "moderateLoss":
finalCalories -= 500; // ~0.5 kg/week loss
break;
case "extremeLoss":
finalCalories -= 1000; // ~1 kg/week loss
break;
case "mildGain":
finalCalories += 250; // ~0.25 kg/week gain
break;
case "moderateGain":
finalCalories += 500; // ~0.5 kg/week gain
break;
case "extremeGain":
finalCalories += 1000; // ~1 kg/week gain
break;
}
// Ensure calories don't go too low for safety, especially for extreme loss
if (finalCalories < 1200 && gender === "female") {
finalCalories = 1200;
errorDiv.innerHTML = "Warning: Calculated calories for extreme loss are very low. A minimum of 1200 calories is recommended for adult females. Consult a professional.";
errorDiv.style.display = "block";
} else if (finalCalories < 1500 && gender === "male") {
finalCalories = 1500;
errorDiv.innerHTML = "Warning: Calculated calories for extreme loss are very low. A minimum of 1500 calories is recommended for adult males. Consult a professional.";
errorDiv.style.display = "block";
}
dailyCaloriesSpan.innerHTML = Math.round(finalCalories) + " calories/day";
resultDiv.style.display = "block";
}
Daily Calorie Needs Calculator
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/week)
Extra Active (very hard exercise/physical job/training twice a day)
Maintain Current Weight
Mild Weight Loss (0.25 kg/week)
Moderate Weight Loss (0.5 kg/week)
Extreme Weight Loss (1 kg/week)
Mild Weight Gain (0.25 kg/week)
Moderate Weight Gain (0.5 kg/week)
Extreme Weight Gain (1 kg/week)
Your estimated daily calorie needs:
Understanding Your Daily Calorie Needs
Knowing your daily calorie needs is a fundamental step towards achieving your weight management goals, whether you aim to lose, gain, or maintain your current weight. This calculator uses the widely accepted Mifflin-St Jeor equation, combined with your activity level and specific goals, to provide a personalized estimate.
What is BMR and TDEE?
- Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest to perform basic life-sustaining functions like breathing, circulation, cell production, and nutrient processing. It's the minimum amount of energy your body needs to simply exist.
- Total Daily Energy Expenditure (TDEE): This represents the total number of calories your body burns in a 24-hour period, including your BMR, the calories burned during physical activity, and the thermic effect of food (calories burned during digestion).
How the Calculator Works
Our calculator uses the following steps to determine your daily calorie needs:
- BMR Calculation: It first calculates your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, which is considered one of the most accurate BMR formulas.
- For Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
- For Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
- Activity Level Adjustment: Your BMR is then multiplied by an activity factor to account for your daily physical activity. This gives you your Total Daily Energy Expenditure (TDEE).
- Sedentary (little or no exercise): BMR × 1.2
- Lightly Active (light exercise/sports 1-3 days/week): BMR × 1.375
- Moderately Active (moderate exercise/sports 3-5 days/week): BMR × 1.55
- Very Active (hard exercise/sports 6-7 days a week): BMR × 1.725
- Extra Active (very hard exercise/physical job/training twice a day): BMR × 1.9
- Goal Adjustment: Finally, your TDEE is adjusted based on your weight goal. To lose weight, a calorie deficit is created; to gain weight, a surplus is added. For example, a 500-calorie deficit per day typically leads to a loss of about 0.5 kg (1 pound) per week.
Realistic Examples:
Let's consider a few scenarios:
- Example 1: Maintenance for an Active Male
A 30-year-old male, 175 cm tall, weighing 70 kg, who is "Very Active" and wants to "Maintain Current Weight".
BMR: (10 * 70) + (6.25 * 175) – (5 * 30) + 5 = 700 + 1093.75 – 150 + 5 = 1648.75 calories.
TDEE (Very Active): 1648.75 * 1.725 = ~2844 calories.
Daily Calorie Needs: Approximately 2844 calories to maintain weight. - Example 2: Moderate Loss for a Sedentary Female
A 40-year-old female, 160 cm tall, weighing 80 kg, who is "Sedentary" and wants "Moderate Weight Loss".
BMR: (10 * 80) + (6.25 * 160) – (5 * 40) – 161 = 800 + 1000 – 200 – 161 = 1439 calories.
TDEE (Sedentary): 1439 * 1.2 = ~1727 calories.
Goal Adjustment (Moderate Loss – 500 calories): 1727 – 500 = ~1227 calories.
Daily Calorie Needs: Approximately 1227 calories for moderate weight loss.
Important Considerations:
While this calculator provides a good estimate, individual results can vary. Factors like body composition, genetics, hormonal balance, and specific types of exercise can influence your actual calorie expenditure. Always consult with a healthcare professional or a registered dietitian before making significant changes to your diet or exercise routine.