Google Calorie Calculator

Daily Calorie Needs Calculator

Use this calculator to estimate your daily calorie needs based on your age, gender, weight, height, and activity level. It also provides calorie targets for various weight management goals.

function calculateCalories() { var age = parseFloat(document.getElementById("age").value); var weight = parseFloat(document.getElementById("weight").value); var height = parseFloat(document.getElementById("height").value); var genderMale = document.getElementById("genderMale").checked; var activityFactor = parseFloat(document.getElementById("activityLevel").value); var goalAdjustment = parseFloat(document.getElementById("goal").value); var resultDiv = document.getElementById("result"); // Input validation if (isNaN(age) || age <= 0 || isNaN(weight) || weight <= 0 || isNaN(height) || height <= 0) { resultDiv.innerHTML = "Please enter valid positive numbers for age, weight, and height."; return; } var bmr; // Basal Metabolic Rate // Mifflin-St Jeor Equation if (genderMale) { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { // Female bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } var tdee = bmr * activityFactor; // Total Daily Energy Expenditure var targetCalories = tdee + goalAdjustment; resultDiv.innerHTML = "

Your Calorie Estimates:

" + "Basal Metabolic Rate (BMR): " + bmr.toFixed(0) + " calories/day" + "Total Daily Energy Expenditure (TDEE): " + tdee.toFixed(0) + " calories/day" + "Target Daily Calories for Goal: " + targetCalories.toFixed(0) + " calories/day" + "These are estimates. Consult a healthcare professional or registered dietitian for personalized advice."; } .calorie-calculator-container { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: #f9f9f9; padding: 25px; border-radius: 10px; box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1); max-width: 600px; margin: 30px auto; color: #333; border: 1px solid #e0e0e0; } .calorie-calculator-container h2 { color: #2c3e50; text-align: center; margin-bottom: 20px; font-size: 1.8em; } .calorie-calculator-container p { line-height: 1.6; margin-bottom: 15px; font-size: 0.95em; } .calculator-form .form-group { margin-bottom: 18px; display: flex; flex-direction: column; } .calculator-form label { font-weight: bold; margin-bottom: 8px; color: #555; font-size: 0.9em; } .calculator-form input[type="number"], .calculator-form select { width: 100%; padding: 10px 12px; border: 1px solid #ccc; border-radius: 5px; font-size: 1em; box-sizing: border-box; transition: border-color 0.3s ease; } .calculator-form input[type="number"]:focus, .calculator-form select:focus { border-color: #007bff; outline: none; box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25); } .calculator-form input[type="radio"] { margin-right: 5px; margin-left: 15px; } .calculator-form input[type="radio"] + label { font-weight: normal; margin-bottom: 0; display: inline-block; margin-right: 10px; } .calculator-form button { background-color: #28a745; color: white; padding: 12px 25px; border: none; border-radius: 5px; cursor: pointer; font-size: 1.1em; font-weight: bold; margin-top: 20px; width: 100%; transition: background-color 0.3s ease, transform 0.2s ease; } .calculator-form button:hover { background-color: #218838; transform: translateY(-2px); } .calculator-result { background-color: #e9f7ef; border: 1px solid #d4edda; border-radius: 8px; padding: 20px; margin-top: 25px; font-size: 1.05em; color: #155724; } .calculator-result h3 { color: #218838; margin-top: 0; margin-bottom: 15px; font-size: 1.4em; text-align: center; } .calculator-result p { margin-bottom: 10px; } .calculator-result strong { color: #0f5132; } .calculator-result .disclaimer { font-size: 0.85em; color: #6c757d; margin-top: 20px; text-align: center; }

Understanding Your Daily Calorie Needs

A calorie calculator is a tool designed to estimate the number of calories your body needs daily to maintain, lose, or gain weight. It takes into account several factors, including your age, gender, weight, height, and activity level, to provide a personalized estimate.

Basal Metabolic Rate (BMR) vs. Total Daily Energy Expenditure (TDEE)

• Basal Metabolic Rate (BMR): This is the minimum number of calories your body needs to perform basic, life-sustaining functions while at rest. This includes breathing, circulation, cell production, nutrient processing, and organ function. Your BMR accounts for about 60-75% of the calories you burn each day.
• Total Daily Energy Expenditure (TDEE): This is the total number of calories you burn in a 24-hour period, including your BMR and the calories expended through physical activity and the thermic effect of food (the energy used to digest, absorb, and metabolize food).

How the Calculator Works: The Mifflin-St Jeor Equation

This calculator uses the widely recognized Mifflin-St Jeor equation to determine your BMR. This formula is considered one of the most accurate for estimating BMR:

• 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

Once your BMR is calculated, it's multiplied by an activity factor to estimate your TDEE. This factor accounts for how much exercise and movement you do throughout your day.

Activity Levels Explained:

• Sedentary: Little or no exercise. You spend most of your day sitting.
• Lightly Active: Light exercise or sports 1-3 days per week.
• Moderately Active: Moderate exercise or sports 3-5 days per week.
• Very Active: Hard exercise or sports 6-7 days a week.
• Extra Active: Very hard exercise, a physically demanding job, or training twice a day.

Adjusting for Your Weight Goal:

After calculating your TDEE, the calculator adjusts your calorie intake based on your chosen weight goal. Generally:

• To Lose Weight: You need to consume fewer calories than your TDEE (create a calorie deficit). A deficit of 500 calories per day typically leads to a loss of about 0.5 kg (1 pound) per week.
• To Gain Weight: You need to consume more calories than your TDEE (create a calorie surplus). A surplus of 500 calories per day typically leads to a gain of about 0.5 kg (1 pound) per week.
• To Maintain Weight: You should aim to consume calories roughly equal to your TDEE.

Example Calculation:

Let's consider a 30-year-old moderately active male, weighing 70 kg and 175 cm tall, aiming to maintain his weight.

1. BMR Calculation: (10 × 70) + (6.25 × 175) – (5 × 30) + 5 = 700 + 1093.75 – 150 + 5 = 1648.75 calories.
2. TDEE Calculation: For a moderately active individual, the activity factor is 1.55. So, 1648.75 × 1.55 = 2555.56 calories.
3. Target Daily Calories: Since the goal is to maintain weight, the target is approximately 2556 calories per day.

If this same individual wanted to lose 0.5 kg per week, their target daily calories would be 2556 – 500 = 2056 calories.

Important Considerations:

While this calculator provides a good estimate, individual results can vary. Factors like body composition (muscle vs. fat), genetics, hormonal balance, and certain medical conditions can influence your actual calorie needs. Always consult with a healthcare professional or a registered dietitian before making significant changes to your diet or exercise routine.