Free Calorie Calculator

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Daily Calorie Needs Calculator

Estimate your daily calorie requirements based on your age, gender, weight, height, activity level, and fitness goals.

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/physical job)
Maintain Weight Mild Weight Loss (approx. 0.25-0.5 kg/week) Moderate Weight Loss (approx. 0.5-1 kg/week) Mild Weight Gain (approx. 0.25-0.5 kg/week) Moderate Weight Gain (approx. 0.5-1 kg/week)
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 activityLevel = document.getElementById('activityLevel').value; var goal = document.getElementById('goal').value; var resultDiv = document.getElementById('calorieResult'); // 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; } // Mifflin-St Jeor Equation for BMR (Basal Metabolic Rate) // 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 var bmr; if (genderMale) { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { // Female bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } // Activity Level Multipliers (PAL – Physical Activity Level) var activityMultiplier; switch (activityLevel) { case 'sedentary': activityMultiplier = 1.2; break; case 'lightlyActive': activityMultiplier = 1.375; break; case 'moderatelyActive': activityMultiplier = 1.55; break; case 'veryActive': activityMultiplier = 1.725; break; case 'extraActive': activityMultiplier = 1.9; break; default: activityMultiplier = 1.55; // Default to moderately active } // TDEE (Total Daily Energy Expenditure) var tdee = bmr * activityMultiplier; // Adjust for Goal var targetCalories = tdee; var goalDescription = ""; switch (goal) { case 'maintain': goalDescription = "to maintain your current weight"; break; case 'mildLoss': targetCalories -= 250; // Approx 0.25-0.5 kg/week loss goalDescription = "for mild weight loss"; break; case 'moderateLoss': targetCalories -= 500; // Approx 0.5-1 kg/week loss goalDescription = "for moderate weight loss"; break; case 'mildGain': targetCalories += 250; // Approx 0.25-0.5 kg/week gain goalDescription = "for mild weight gain"; break; case 'moderateGain': targetCalories += 500; // Approx 0.5-1 kg/week gain goalDescription = "for moderate weight gain"; break; } // Ensure target calories don't go too low for safety if (targetCalories < 1000 && goal.includes("Loss")) { targetCalories = 1000; // A reasonable floor for calorie intake goalDescription += " (Note: Adjusted to a minimum of 1000 calories for safety)"; } resultDiv.innerHTML = '

Your Estimated Daily Calorie Needs:

' + 'Your Basal Metabolic Rate (BMR): ' + Math.round(bmr) + ' calories/day' + 'Your Total Daily Energy Expenditure (TDEE): ' + Math.round(tdee) + ' calories/day' + 'Your estimated daily calorie intake ' + goalDescription + ' is: ' + Math.round(targetCalories) + ' calories/day' + 'These are estimates. Individual needs may vary. Consult a healthcare professional or registered dietitian for personalized advice.'; } .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; border: 1px solid #e0e0e0; } .calculator-container h2 { color: #333; text-align: center; margin-bottom: 20px; font-size: 1.8em; } .calculator-container p { color: #555; line-height: 1.6; margin-bottom: 15px; } .calc-input-group { margin-bottom: 18px; display: flex; flex-direction: column; } .calc-input-group label { margin-bottom: 8px; color: #333; font-weight: bold; font-size: 0.95em; } .calc-input-group input[type="number"], .calc-input-group select { padding: 10px 12px; border: 1px solid #ccc; border-radius: 5px; font-size: 1em; width: 100%; box-sizing: border-box; transition: border-color 0.3s ease; } .calc-input-group input[type="number"]:focus, .calc-input-group select:focus { border-color: #007bff; outline: none; box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25); } .calc-input-group input[type="radio"] { margin-right: 5px; margin-left: 15px; } .calc-input-group input[type="radio"] + label { font-weight: normal; color: #555; display: inline-block; margin-bottom: 0; } .calc-input-group input[type="radio"]:first-of-type { margin-left: 0; } button { background-color: #007bff; color: white; padding: 12px 25px; border: none; border-radius: 5px; font-size: 1.1em; cursor: pointer; display: block; width: 100%; margin-top: 25px; transition: background-color 0.3s ease, transform 0.2s ease; } button:hover { background-color: #0056b3; transform: translateY(-2px); } .calc-result { background-color: #e9f7ff; border: 1px solid #b3e0ff; padding: 20px; border-radius: 8px; margin-top: 30px; font-size: 1.1em; color: #004085; } .calc-result h3 { color: #0056b3; margin-top: 0; margin-bottom: 15px; font-size: 1.4em; } .calc-result p { margin-bottom: 10px; } .calc-result strong { color: #002752; } .calc-result .disclaimer { font-size: 0.85em; color: #6c757d; margin-top: 20px; border-top: 1px dashed #cce5ff; padding-top: 15px; }

Understanding Your Daily Calorie Needs with a Free Calorie Calculator

Whether your goal is to maintain, lose, or gain weight, understanding your daily calorie needs is the cornerstone of effective nutrition planning. Our free calorie calculator provides an estimate of how many calories your body burns daily and how many you might need to consume to reach your specific fitness goals.

What are Calories and Why Do They Matter?

A calorie is a unit of energy. In nutrition, it refers to the energy we get from food and drinks, and the energy we use for bodily functions and physical activity. Every process in your body, from breathing and thinking to exercising and digesting food, requires energy in the form of calories.

  • Weight Maintenance: If you consume roughly the same number of calories you burn, your weight will likely remain stable.
  • Weight Loss: To lose weight, you generally need to consume fewer calories than your body burns (a calorie deficit).
  • Weight Gain: To gain weight (muscle or fat), you typically need to consume more calories than your body burns (a calorie surplus).

How Our Calorie Calculator Works

Our calculator uses the widely accepted Mifflin-St Jeor Equation to estimate your Basal Metabolic Rate (BMR) and then adjusts this based on your activity level to determine your Total Daily Energy Expenditure (TDEE). Finally, it factors in your weight goal to provide a target calorie intake.

1. Basal Metabolic Rate (BMR)

Your BMR is the 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. It's the minimum amount of energy required to keep you alive. The Mifflin-St Jeor Equation considers:

  • Age: Metabolism tends to slow down with age.
  • Gender: Men generally have higher BMRs than women due to a higher muscle mass percentage.
  • Weight: Heavier individuals typically have higher BMRs.
  • Height: Taller individuals generally have higher BMRs.

2. Total Daily Energy Expenditure (TDEE)

Your TDEE is the total number of calories you burn in a 24-hour period, including your BMR and the calories expended through physical activity. This is calculated by multiplying your BMR by an activity factor:

  • 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, a physically demanding job, or training twice a day.

3. Adjusting for Your Goal

Once your TDEE is calculated, the calculator adjusts this number based on your weight goal:

  • Maintain Weight: Your target calories will be approximately equal to your TDEE.
  • Mild Weight Loss: A small calorie deficit (e.g., 250 calories below TDEE) for gradual, sustainable loss.
  • Moderate Weight Loss: A larger calorie deficit (e.g., 500 calories below TDEE) for a faster rate of loss (typically 0.5-1 kg per week).
  • Mild Weight Gain: A small calorie surplus (e.g., 250 calories above TDEE) for gradual muscle or weight gain.
  • Moderate Weight Gain: A larger calorie surplus (e.g., 500 calories above TDEE) for faster weight gain.

Example Calculation

Let's consider a 30-year-old moderately active male, weighing 70 kg and 175 cm tall, aiming for moderate weight loss:

  1. BMR Calculation: Using the Mifflin-St Jeor formula for men:
    BMR = (10 × 70) + (6.25 × 175) – (5 × 30) + 5
    BMR = 700 + 1093.75 – 150 + 5 = 1648.75 calories.
    (Rounded to 1649 calories)
  2. TDEE Calculation: For a moderately active individual, the multiplier is 1.55:
    TDEE = 1649 × 1.55 = 2555.95 calories.
    (Rounded to 2556 calories)
  3. Goal Adjustment (Moderate Weight Loss): For moderate weight loss, we subtract 500 calories from TDEE:
    Target Calories = 2556 – 500 = 2056 calories.

So, this individual would aim for approximately 2056 calories per day for moderate weight loss.

Important Considerations

While this calculator provides a valuable estimate, remember that it's a general tool. Individual calorie needs can vary based on genetics, body composition (muscle vs. fat), hormonal factors, and specific health conditions. For personalized dietary advice and to ensure your calorie targets are safe and appropriate for your health, always consult with a healthcare professional or a registered dietitian.

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