Calorie and Macro Calculator

Calorie & Macro Calculator

Your Estimated Daily Needs:

Basal Metabolic Rate (BMR): calories/day

Total Daily Energy Expenditure (TDEE): calories/day

Daily Calorie Goal: calories

Macronutrient Breakdown (Example Split: P:30%, F:25%, C:45%):

• Protein: grams ( calories)
• Fats: grams ( calories)
• Carbohydrates: grams ( calories)

function calculateMacros() { var gender = document.getElementById("gender").value; var age = parseFloat(document.getElementById("age").value); var heightCm = parseFloat(document.getElementById("heightCm").value); var weightKg = parseFloat(document.getElementById("weightKg").value); var activityFactor = parseFloat(document.getElementById("activityLevel").value); var goal = document.getElementById("goal").value; var errorMessageDiv = document.getElementById("errorMessage"); var macroResultsDiv = document.getElementById("macroResults"); errorMessageDiv.style.display = "none"; macroResultsDiv.style.display = "none"; // Input validation if (isNaN(age) || age <= 0 || isNaN(heightCm) || heightCm <= 0 || isNaN(weightKg) || weightKg <= 0) { errorMessageDiv.innerHTML = "Please enter valid positive numbers for Age, Height, and Weight."; errorMessageDiv.style.display = "block"; return; } var bmr; // Mifflin-St Jeor Equation if (gender === "male") { bmr = (10 * weightKg) + (6.25 * heightCm) – (5 * age) + 5; } else { // female bmr = (10 * weightKg) + (6.25 * heightCm) – (5 * age) – 161; } var tdee = bmr * activityFactor; var calorieGoal; switch (goal) { case "maintain": calorieGoal = tdee; break; case "mildLoss": calorieGoal = tdee – 250; // Approx 0.25 kg/week loss break; case "moderateLoss": calorieGoal = tdee – 500; // Approx 0.5 kg/week loss break; case "extremeLoss": calorieGoal = tdee – 1000; // Approx 1 kg/week loss break; case "mildGain": calorieGoal = tdee + 250; // Approx 0.25 kg/week gain break; case "moderateGain": calorieGoal = tdee + 500; // Approx 0.5 kg/week gain break; case "extremeGain": calorieGoal = tdee + 1000; // Approx 1 kg/week gain break; default: calorieGoal = tdee; // Fallback to maintain } // Ensure calorie goal doesn't go too low for extreme loss if (calorieGoal < 1200 && gender === "female") calorieGoal = 1200; if (calorieGoal < 1500 && gender === "male") calorieGoal = 1500; // Macro split percentages (example: Protein 30%, Fat 25%, Carbs 45%) var proteinPercentage = 0.30; var fatPercentage = 0.25; var carbPercentage = 0.45; // Calculate calories from each macro var proteinCals = calorieGoal * proteinPercentage; var fatCals = calorieGoal * fatPercentage; var carbCals = calorieGoal * carbPercentage; // Convert calories to grams var proteinGrams = proteinCals / 4; // 4 calories per gram of protein var fatGrams = fatCals / 9; // 9 calories per gram of fat var carbGrams = carbCals / 4; // 4 calories per gram of carbohydrate // Display results document.getElementById("displayBMR").innerHTML = Math.round(bmr); document.getElementById("displayTDEE").innerHTML = Math.round(tdee); document.getElementById("displayCalorieGoal").innerHTML = Math.round(calorieGoal); document.getElementById("displayProteinGrams").innerHTML = Math.round(proteinGrams); document.getElementById("displayProteinCals").innerHTML = Math.round(proteinCals); document.getElementById("displayFatGrams").innerHTML = Math.round(fatGrams); document.getElementById("displayFatCals").innerHTML = Math.round(fatCals); document.getElementById("displayCarbGrams").innerHTML = Math.round(carbGrams); document.getElementById("displayCarbCals").innerHTML = Math.round(carbCals); macroResultsDiv.style.display = "block"; }

Understanding Your Calorie & Macro Needs

Achieving your fitness and health goals, whether it's weight loss, muscle gain, or maintenance, starts with understanding your body's energy requirements. This Calorie & Macro Calculator helps you estimate your daily calorie needs and provides a breakdown of macronutrients (protein, fats, and carbohydrates) to guide your nutrition.

What is BMR (Basal Metabolic Rate)?

Your Basal Metabolic Rate (BMR) is the number of calories your body burns at rest to perform basic life-sustaining functions. This includes breathing, circulation, cell production, nutrient processing, and maintaining body temperature. It's the minimum amount of energy your body needs to simply exist, without any physical activity.

The calculator uses the Mifflin-St Jeor Equation, a widely accepted formula for estimating BMR:

• Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
• Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

What is TDEE (Total Daily Energy Expenditure)?

While BMR accounts for calories burned at rest, your Total Daily Energy Expenditure (TDEE) includes all the calories you burn throughout the day. This encompasses your BMR plus the energy expended through physical activity, digestion (thermic effect of food), and non-exercise activity thermogenesis (NEAT, like fidgeting or walking around).

Your TDEE is calculated by multiplying your BMR by an activity factor:

• 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
• Extremely active (very hard exercise/physical job): BMR × 1.9

Your TDEE is the number of calories you need to consume to maintain your current weight.

Setting Your Calorie Goal

Once your TDEE is established, you can adjust your calorie intake based on your specific goal:

• Maintain Weight: Consume calories equal to your TDEE.
• Weight Loss: To lose weight, you need to 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. Our calculator offers mild, moderate, and extreme loss options.
• Weight Gain (Muscle Mass): To gain weight, particularly muscle, you need a calorie surplus. A surplus of 250-500 calories per day is often recommended for sustainable gain. Our calculator offers mild, moderate, and extreme gain options.

Important Note: For health and safety, the calculator ensures that calorie goals do not fall below 1200 calories for females and 1500 calories for males, as consuming too few calories can be detrimental to health and metabolism.

Understanding Macronutrients (Macros)

Macronutrients are the nutrients your body needs in large amounts for energy and to perform various bodily functions. They include Protein, Fats, and Carbohydrates.

• Protein: Essential for building and repairing tissues, making enzymes and hormones, and supporting immune function. Each gram of protein provides 4 calories. Common recommendations range from 1.6 to 2.2 grams per kg of body weight, or 25-35% of total calories.
• Fats: Crucial for hormone production, nutrient absorption, cell membrane integrity, and providing a concentrated source of energy. Each gram of fat provides 9 calories. Healthy fat intake typically ranges from 20-30% of total calories.
• Carbohydrates: The body's primary source of energy, fueling your brain and muscles. Each gram of carbohydrate provides 4 calories. The remaining percentage of your calorie goal after protein and fats is typically allocated to carbohydrates (e.g., 40-55%).

The calculator provides an example macro split (30% Protein, 25% Fats, 45% Carbohydrates) which is a common starting point for many fitness goals. You may adjust these percentages based on specific dietary preferences, health conditions, or professional advice.

How to Use Your Results

Use the calculated calorie goal and macro breakdown as a guideline. Track your food intake using an app or food diary to ensure you're hitting your targets. Monitor your progress (weight, measurements, energy levels) and adjust your intake as needed. Consistency and patience are key to achieving your desired results!