My Macro Calculator

My Daily Macro Calculator

Use this calculator to estimate your daily caloric needs and macronutrient breakdown (protein, carbohydrates, and fats) based on your personal data and fitness goals.

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weight * 0.453592 : weight; // Convert height to cm var heightCm = (heightUnit === "inches") ? height * 2.54 : height; // Step 1: Calculate Basal Metabolic Rate (BMR) using Mifflin-St Jeor Equation var bmr; if (gender === "male") { bmr = (10 * weightKg) + (6.25 * heightCm) – (5 * age) + 5; } else { // female bmr = (10 * weightKg) + (6.25 * heightCm) – (5 * age) – 161; } // Step 2: Calculate Total Daily Energy Expenditure (TDEE) var activityFactor; switch (activityLevel) { case "sedentary": activityFactor = 1.2; break; case "lightlyActive": activityFactor = 1.375; break; case "moderatelyActive": activityFactor = 1.55; break; case "veryActive": activityFactor = 1.725; break; case "extraActive": activityFactor = 1.9; break; default: activityFactor = 1.2; // Default to sedentary } var tdee = bmr * activityFactor; // Step 3: Adjust TDEE for Goal var totalCalories; switch (goal) { case "maintain": totalCalories = tdee; break; case "mildLoss": totalCalories = tdee – 300; // Approx 0.25 kg/week loss break; case "moderateLoss": totalCalories = tdee – 500; // Approx 0.5 kg/week loss break; case "mildGain": totalCalories = tdee + 300; // Approx 0.25 kg/week gain break; case "moderateGain": totalCalories = tdee + 500; // Approx 0.5 kg/week gain break; default: totalCalories = tdee; // Default to maintain } // Ensure total calories don't go too low for health if (totalCalories < 1000) { totalCalories = 1000; } // Step 4: Calculate Macronutrients var proteinCal = totalCalories * (proteinPercentage / 100); var fatCal = totalCalories * (fatPercentage / 100); var carbCal = totalCalories – proteinCal – fatCal; // Ensure carb calories are not negative due to high protein/fat percentages if (carbCal < 0) { carbCal = 0; // Redistribute the "missing" carb calories to fat, then protein if needed fatCal = totalCalories – proteinCal; if (fatCal < 0) { fatCal = 0; proteinCal = totalCalories; // All remaining calories to protein } } var proteinGrams = proteinCal / 4; // 1g protein = 4 calories var carbGrams = carbCal / 4; // 1g carbs = 4 calories var fatGrams = fatCal / 9; // 1g fat = 9 calories // Display results document.getElementById("totalCaloriesResult").innerText = Math.round(totalCalories); document.getElementById("proteinGramsResult").innerText = Math.round(proteinGrams); document.getElementById("proteinCalResult").innerText = Math.round(proteinCal); document.getElementById("carbGramsResult").innerText = Math.round(carbGrams); document.getElementById("carbCalResult").innerText = Math.round(carbCal); document.getElementById("fatGramsResult").innerText = Math.round(fatGrams); document.getElementById("fatCalResult").innerText = Math.round(fatCal); } // Run calculation on page load with default values window.onload = calculateMacros;

Understanding Your Macros: The Key to Personalized Nutrition

Macronutrients, often shortened to "macros," are the three main categories of nutrients your body needs in large amounts for energy and to perform essential functions: protein, carbohydrates, and fats. Unlike micronutrients (vitamins and minerals), macros provide calories and are crucial for everything from muscle growth and repair to brain function and hormone production.

Why Track Macros?

While simply counting calories can help with weight management, tracking macros offers a more nuanced approach to nutrition. It allows you to:

• Optimize Body Composition: By adjusting your protein, carb, and fat intake, you can prioritize muscle gain, fat loss, or maintenance more effectively than just focusing on total calories.
• Improve Performance: Athletes and active individuals can tailor their carb intake for energy, protein for recovery, and fats for sustained fuel.
• Manage Health Conditions: Specific macro ratios can be beneficial for conditions like diabetes (carb management) or heart health (fat quality).
• Personalize Your Diet: Everyone responds differently to various macro splits. Tracking helps you discover what works best for your body, energy levels, and satiety.

How the Macro Calculator Works

Our calculator uses a multi-step process to provide a personalized macro breakdown:

1. Basal Metabolic Rate (BMR) Calculation: This is the number of calories your body burns at rest to maintain basic life functions (breathing, circulation, cell production). We use the widely accepted Mifflin-St Jeor equation, which considers your gender, age, weight, and height.
2. Total Daily Energy Expenditure (TDEE) Calculation: Your BMR is then multiplied by an activity factor to estimate the total calories you burn in a day, including exercise and daily movement.
3. Goal Adjustment: Based on your selected goal (maintain, mild loss, moderate loss, mild gain, moderate gain), your TDEE is adjusted to create a caloric deficit or surplus. For example, a moderate weight loss goal typically involves a 500-calorie deficit per day, aiming for approximately 0.5 kg (1 lb) of fat loss per week.
4. Macronutrient Split: Finally, the adjusted total calories are divided into protein, carbohydrates, and fats based on your preferred percentages. If you don't have specific preferences, the calculator uses common recommendations (e.g., 30% protein, 25% fat, 45% carbs) as a starting point.

Understanding Your Results

The calculator provides your estimated daily intake for:

• Total Calories: Your target caloric intake for your chosen goal.
• Protein (grams and calories): Essential for muscle repair, growth, and satiety. Generally, active individuals benefit from higher protein intake (e.g., 1.6-2.2 grams per kg of body weight).
• Carbohydrates (grams and calories): Your body's primary energy source. Important for fueling workouts and daily activities.
• Fats (grams and calories): Crucial for hormone production, nutrient absorption, and overall health. Healthy fats are vital.

Example Calculation:

Let's consider a 30-year-old male, 175 cm tall, weighing 70 kg, who is moderately active and aims for moderate weight loss, with a macro split of 30% protein, 25% fat, and 45% carbs.

1. BMR Calculation (Mifflin-St Jeor for Male):
   BMR = (10 * 70 kg) + (6.25 * 175 cm) – (5 * 30 years) + 5
   BMR = 700 + 1093.75 – 150 + 5 = 1648.75 kcal
2. TDEE Calculation (Moderately Active):
   TDEE = 1648.75 kcal * 1.55 (activity factor)
   TDEE = 2555.56 kcal
3. Goal Adjustment (Moderate Weight Loss):
   Adjusted Calories = 2555.56 kcal – 500 kcal
   Adjusted Calories = 2055.56 kcal (approx. 2056 kcal)
4. Macronutrient Split:
   • Protein (30%):
     Calories = 2056 * 0.30 = 616.8 kcal
     Grams = 616.8 / 4 = 154.2 g
   • Fat (25%):
     Calories = 2056 * 0.25 = 514 kcal
     Grams = 514 / 9 = 57.1 g
   • Carbohydrates (45%):
     Calories = 2056 * 0.45 = 925.2 kcal
     Grams = 925.2 / 4 = 231.3 g

So, for this individual, the estimated daily macros would be approximately 2056 kcal, 154g Protein, 231g Carbs, and 57g Fat.

Important Considerations:

• Food Quality: While macros are important, the quality of your food sources matters immensely. Prioritize whole, unprocessed foods.
• Individual Variation: These calculations are estimates. Metabolism, genetics, and other factors can influence actual needs. Adjust your intake based on how your body responds.
• Hydration and Micronutrients: Don't forget water, vitamins, and minerals, which are vital for overall health.
• Consult a Professional: For specific dietary needs, health conditions, or advanced fitness goals, always consult a registered dietitian or healthcare provider.