How to Calculate Your Own Macros for Weight Loss

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Calculate Your Macros for Weight Loss

Discover your personalized macronutrient targets for effective and sustainable weight loss.

Macro Calculator for Weight Loss

Enter your current weight in kilograms.
Enter your height in centimeters.
Enter your age in years.
Male Female
Sedentary (little to 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/sports & physical job)
Recommended: 0.25 to 1 kg per week.

Your Personalized Macro Targets for Weight Loss

— kcal
Formula Used: We first estimate your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, then adjust it for your activity level to find your Total Daily Energy Expenditure (TDEE). Finally, we create a calorie deficit based on your weight loss goal and distribute those calories among protein, carbohydrates, and fats.

Target Calories (TDEE)

kcal/day

Calorie Deficit

kcal/day

Protein

grams/day

Carbohydrates

grams/day

Fat

grams/day

Macronutrient Distribution

Distribution of your daily calories among Protein, Carbohydrates, and Fat.

Key Variables Used in Calculation

Variables and Their Impact on Macro Calculation
Variable Meaning Unit Typical Range
Current Weight Your body mass. Heavier individuals generally require more calories. kg 20 – 500+
Height Body size; influences BMR. cm 50 – 250
Age Metabolic rate tends to decrease with age. Years 1 – 120
Gender Men typically have higher muscle mass and thus higher BMR. Category Male, Female
Activity Level Daily movement and exercise impact calorie expenditure. Category Sedentary to Extra Active
Weight Loss Goal Determines the calorie deficit required. kg/week 0.1 – 2.0

What is Calculating Your Own Macros for Weight Loss?

Calculating your own macros for weight loss involves determining the precise amounts of macronutrients – protein, carbohydrates, and fats – your body needs to achieve a calorie deficit while supporting essential bodily functions and preserving muscle mass. Instead of following generic diet plans, this personalized approach allows you to understand your energy needs and adjust your food intake accordingly. It's a cornerstone of flexible dieting, often referred to as "If It Fits Your Macros" (IIFYM), which emphasizes hitting target nutrient numbers rather than restricting specific foods.

Who Should Use It: Anyone aiming for sustainable weight loss, fitness enthusiasts looking to optimize body composition, individuals who want more control over their diet without extreme restrictions, and people who have found traditional diets ineffective. It's particularly useful for those who understand basic nutrition but need a structured way to apply that knowledge for weight management. It's also beneficial for individuals with specific dietary needs or preferences who want to integrate them into a weight loss plan.

Common Misconceptions:

  • Macros are rigid and restrictive: While targets are set, flexible dieting allows for variety. The focus is on hitting numbers, not on specific "good" or "bad" foods.
  • All calories are equal: While a calorie deficit is key, the source of calories (macros) significantly impacts satiety, muscle retention, and overall health.
  • You need to weigh every food: While precise tracking can be helpful, understanding portion sizes and estimating can also work once you've built a foundation.
  • It's only for bodybuilders: This method is highly effective for general weight loss and health improvement for anyone.
Understanding how to calculate your own macros for weight loss empowers you to take control of your nutrition journey effectively.

Macro Calculation Formula and Mathematical Explanation

The process of calculating your own macros for weight loss involves several steps, starting with estimating your energy needs and then creating a deficit. We'll use the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), adjust it for activity level to find your Total Daily Energy Expenditure (TDEE), and then subtract calories for your desired deficit.

Step 1: Estimate Basal Metabolic Rate (BMR)

BMR is the number of calories your body burns at rest to maintain basic functions. The Mifflin-St Jeor equation is considered one of the most accurate:

  • 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

Step 2: Calculate Total Daily Energy Expenditure (TDEE)

TDEE accounts for your activity level. Multiply your BMR by an activity factor:

  • Sedentary: BMR * 1.2
  • Lightly Active: BMR * 1.375
  • Moderately Active: BMR * 1.55
  • Very Active: BMR * 1.725
  • Extra Active: BMR * 1.9

This TDEE is the approximate number of calories you need to maintain your current weight.

Step 3: Determine Calorie Deficit for Weight Loss

To lose weight, you need to consume fewer calories than your TDEE. A safe and sustainable deficit is typically 500-1000 calories per day, aiming for 0.5-1 kg (1-2 lbs) of fat loss per week. One kilogram of fat is roughly equivalent to 7700 calories.

Calorie Deficit = (Desired Weight Loss per Week in kg) * 7700 kcal / 7 days

Target Daily Calories = TDEE – Calorie Deficit

Step 4: Calculate Macronutrient Distribution

Once you have your target daily calories, you distribute them among protein, carbohydrates, and fats. Here are common recommendations for weight loss:

  • Protein: Crucial for muscle preservation and satiety. Aim for 1.6-2.2 grams per kg of body weight. (4 kcal per gram)
  • Fat: Essential for hormone production and nutrient absorption. Aim for 20-30% of total daily calories. (9 kcal per gram)
  • Carbohydrates: Provide energy. The remaining calories after protein and fat are allocated to carbohydrates. (4 kcal per gram)

Example Calculation Breakdown:

Let's say your Target Daily Calories = 2000 kcal.

  • If your current weight is 70kg: Protein = 70kg * 1.8 g/kg = 126g.
  • Calories from Protein = 126g * 4 kcal/g = 504 kcal.
  • If Fat is 25% of total calories: Fat Calories = 2000 kcal * 0.25 = 500 kcal.
  • Fat in grams = 500 kcal / 9 kcal/g = ~56g.
  • Remaining calories for Carbs = 2000 kcal – 504 kcal (Protein) – 500 kcal (Fat) = 996 kcal.
  • Carbohydrates in grams = 996 kcal / 4 kcal/g = ~249g.

Variable Explanations Table

Macro Calculation Variables
Variable Meaning Unit Typical Range
Weight Current body mass. kg 20 – 500+
Height Body dimension influencing BMR. cm 50 – 250
Age Factor in metabolic rate. Years 1 – 120
Gender Influences BMR calculation. Category Male, Female
Activity Level Multiplier for TDEE calculation. Category Sedentary to Extra Active
Weight Loss Goal Defines the daily calorie deficit. kg/week 0.1 – 2.0
Protein Target Grams of protein per kg of body weight. g/kg 1.6 – 2.2
Fat Percentage Percentage of total calories from fat. % 20 – 30

Practical Examples (Real-World Use Cases)

Example 1: Sarah, aiming for sustainable fat loss

Inputs:

  • Current Weight: 65 kg
  • Height: 165 cm
  • Age: 28
  • Gender: Female
  • Activity Level: Moderately Active
  • Weight Loss Goal: 0.5 kg/week
Calculation Process:
  1. BMR (Female) = (10 * 65) + (6.25 * 165) – (5 * 28) – 161 = 650 + 1031.25 – 140 – 161 = 1380.25 kcal
  2. TDEE = 1380.25 * 1.55 (Moderately Active) = 2139.39 kcal
  3. Calorie Deficit for 0.5 kg/week = (0.5 * 7700) / 7 = 550 kcal/day
  4. Target Daily Calories = 2139.39 – 550 = 1589.39 kcal (Round to 1590 kcal)
  5. Protein: 65 kg * 1.8 g/kg = 117g (117g * 4 kcal/g = 468 kcal)
  6. Fat: Let's aim for 25% of calories. 1590 kcal * 0.25 = 397.5 kcal. 397.5 kcal / 9 kcal/g = ~44g
  7. Carbohydrates: 1590 kcal (Total) – 468 kcal (Protein) – 397.5 kcal (Fat) = 724.5 kcal. 724.5 kcal / 4 kcal/g = ~181g
Results for Sarah:
  • Target Daily Calories: ~1590 kcal
  • Protein: ~117 grams
  • Fat: ~44 grams
  • Carbohydrates: ~181 grams

Interpretation: Sarah needs approximately 1590 calories per day, with a focus on 117g protein, 44g fat, and 181g carbs to lose about half a kilogram per week. This allows her to eat a variety of foods while staying within her calorie and macro targets, supporting muscle retention and satiety during her weight loss journey.

Example 2: Mark, focusing on muscle preservation during weight loss

Inputs:

  • Current Weight: 85 kg
  • Height: 180 cm
  • Age: 35
  • Gender: Male
  • Activity Level: Very Active
  • Weight Loss Goal: 0.75 kg/week
Calculation Process:
  1. BMR (Male) = (10 * 85) + (6.25 * 180) – (5 * 35) + 5 = 850 + 1125 – 175 + 5 = 1805 kcal
  2. TDEE = 1805 * 1.725 (Very Active) = 3114.13 kcal
  3. Calorie Deficit for 0.75 kg/week = (0.75 * 7700) / 7 = 825 kcal/day
  4. Target Daily Calories = 3114.13 – 825 = 2289.13 kcal (Round to 2290 kcal)
  5. Protein: 85 kg * 2.0 g/kg = 170g (170g * 4 kcal/g = 680 kcal)
  6. Fat: Let's aim for 20% of calories. 2290 kcal * 0.20 = 458 kcal. 458 kcal / 9 kcal/g = ~51g
  7. Carbohydrates: 2290 kcal (Total) – 680 kcal (Protein) – 458 kcal (Fat) = 1152 kcal. 1152 kcal / 4 kcal/g = ~288g
Results for Mark:
  • Target Daily Calories: ~2290 kcal
  • Protein: ~170 grams
  • Fat: ~51 grams
  • Carbohydrates: ~288 grams

Interpretation: Mark requires approximately 2290 calories daily. With a higher protein intake of 170g to support muscle mass during intense training and weight loss, combined with 51g of fat and 288g of carbohydrates, he can effectively pursue his goal of losing about 0.75kg weekly while maintaining strength and performance.

How to Use This Macro Calculator for Weight Loss

Using our calculator to determine your personalized macros for weight loss is straightforward. Follow these steps:

  1. Input Your Details: Accurately enter your current weight, height, age, gender, and select your typical daily activity level from the dropdown menu.
  2. Set Your Weight Loss Goal: Specify your desired weekly weight loss in kilograms. A rate of 0.5kg to 1kg per week is generally recommended for sustainable results.
  3. Calculate: Click the "Calculate Macros" button.

How to Read Results:

  • Main Result (Target Calories): This is the total number of calories you should aim to consume daily for your specified weight loss goal.
  • Intermediate Values: These show your calculated TDEE (Total Daily Energy Expenditure – calories to maintain weight), the necessary Calorie Deficit, and the recommended daily grams for Protein, Fat, and Carbohydrates.
  • Macro Distribution Chart: Visually represents how your target calories are split among the three macronutrients.
  • Key Assumptions Table: Reviews the variables used and their typical ranges, providing context for the calculation.

Decision-Making Guidance: Use these targets as a starting point. Monitor your progress for 2-3 weeks. If you're not losing weight as expected, you might need to slightly decrease your calorie intake or increase activity. If you feel overly fatigued or are losing weight too quickly, you may need to slightly increase your calories. Adjustments based on your body's response are key to finding your optimal macro split for weight loss.

Key Factors That Affect Macro Calculation Results

Several factors can influence the accuracy and effectiveness of your calculated macro targets:

  1. Body Composition: Muscle tissue burns more calories than fat. Individuals with higher muscle mass may have a higher TDEE than someone of the same weight and height with less muscle. Our calculator uses general formulas, but body composition can lead to individual variations.
  2. Metabolic Adaptations: Over time, as you lose weight or diet for extended periods, your metabolism can adapt and slow down. This means your TDEE might decrease, requiring adjustments to your calorie intake to continue losing weight.
  3. Hormonal Fluctuations: Hormones related to stress (cortisol), sleep, and menstrual cycles (in women) can affect appetite, water retention, and metabolism, indirectly influencing weight loss and nutrient partitioning.
  4. Dietary Adherence and Accuracy: The accuracy of your food tracking is paramount. Miscalculating portion sizes, underestimating calorie-dense foods, or frequent "cheat meals" can significantly derail progress, making the calculated macros less effective.
  5. Individual Digestion and Nutrient Absorption: While the 4-9-4 kcal/gram values are standard, individual absorption rates can vary slightly, though this is usually a minor factor for most people.
  6. Exercise Intensity and Type: The activity level multipliers are estimates. The specific type, duration, and intensity of your workouts can significantly impact your actual daily calorie expenditure, requiring you to fine-tune your intake based on your energy levels and performance.
  7. Sleep Quality: Poor sleep can disrupt hormones that regulate appetite (ghrelin and leptin) and increase cortisol, potentially hindering weight loss and increasing cravings for high-calorie foods.
  8. Hydration Levels: While not a direct macro factor, adequate water intake is crucial for metabolic processes and can influence feelings of fullness, aiding in calorie control.

Frequently Asked Questions (FAQ)

What is the best macro split for weight loss?
There isn't a single "best" split for everyone. A common starting point is high protein (1.6-2.2g/kg), moderate carbohydrates, and lower fat (20-30% of calories). However, the most effective split is one that is sustainable for you, keeps you full, supports your activity, and allows you to adhere to a calorie deficit. Experimentation based on your calculated targets is key.
Do I need to track my macros precisely forever?
Not necessarily. Initially, precise tracking helps you learn portion sizes and understand the macro content of foods. Once you become proficient, you can transition to more intuitive eating while still keeping your targets in mind, or use periodic tracking to stay on course. The goal is long-term sustainable habits.
Can I adjust my macros if I feel too hungry or too full?
Yes. If you're consistently hungry, you might increase protein or fiber-rich carbohydrates. If you're feeling too full or sluggish, you might slightly adjust fat or carb ratios. Always ensure you are still within your target calorie range for weight loss.
What if my weight loss stalls?
Stalls are common. Re-evaluate your food tracking accuracy, check for non-scale victories (like improved energy or clothing fit), consider a small calorie adjustment (downward), or incorporate more NEAT (Non-Exercise Activity Thermogenesis) or structured exercise. Ensure your calculated macros are still appropriate for your current weight, not your goal weight.
Does carb cycling help with weight loss?
Carb cycling involves varying carbohydrate intake on different days. For some, it can help manage energy levels and potentially improve adherence. However, it's not inherently superior to a consistent macro approach for overall fat loss, which primarily depends on a calorie deficit. It can be a tool for those who respond well to it.
How does exercise affect my macro calculations?
Exercise increases your Total Daily Energy Expenditure (TDEE), meaning you burn more calories. While our calculator accounts for general activity levels, intense or prolonged exercise might require slightly higher calorie intake, particularly from carbohydrates, to fuel performance and recovery. Listen to your body and adjust accordingly.
Is it okay to prioritize certain macros over others?
For weight loss, prioritizing protein is often recommended for satiety and muscle preservation. Beyond that, the distribution between fats and carbs can be more flexible based on personal preference and tolerance, as long as the total calorie target is met. Extreme restriction of any macro group can be detrimental.
What are the best food sources for each macro?
  • Protein: Lean meats (chicken, turkey, beef), fish, eggs, dairy (Greek yogurt, cottage cheese), legumes, tofu, protein powders.
  • Carbohydrates: Whole grains (oats, quinoa, brown rice), fruits, vegetables, legumes, starchy vegetables (potatoes, sweet potatoes).
  • Fats: Avocados, nuts, seeds, olive oil, fatty fish (salmon, mackerel), nut butters.
Focusing on whole, unprocessed foods within each category is beneficial for overall health.

Disclaimer: This calculator provides estimations based on provided data. Consult with a healthcare professional or registered dietitian for personalized advice.

var currentWeightInput = document.getElementById('currentWeight'); var heightInput = document.getElementById('height'); var ageInput = document.getElementById('age'); var genderSelect = document.getElementById('gender'); var activityLevelSelect = document.getElementById('activityLevel'); var weightLossGoalInput = document.getElementById('weightLossGoal'); var currentWeightError = document.getElementById('currentWeightError'); var heightError = document.getElementById('heightError'); var ageError = document.getElementById('ageError'); var weightLossGoalError = document.getElementById('weightLossGoalError'); var mainResultDiv = document.getElementById('main-result'); var targetTDEEDiv = document.getElementById('targetTDEE'); var calorieDeficitDiv = document.getElementById('calorieDeficit'); var proteinGramsDiv = document.getElementById('proteinGrams'); var carbGramsDiv = document.getElementById('carbGrams'); var fatGramsDiv = document.getElementById('fatGrams'); var macroChartCanvas = document.getElementById('macroChart'); var macroChartContext = macroChartCanvas.getContext('2d'); var macroChartInstance = null; function validateInput(inputElement, errorElement, minValue, maxValue, name) { var value = parseFloat(inputElement.value); var isValid = true; errorElement.textContent = "; if (isNaN(value)) { errorElement.textContent = name + ' must be a number.'; isValid = false; } else if (value maxValue) { errorElement.textContent = name + ' cannot be greater than ' + maxValue + '.'; isValid = false; } return isValid; } function calculateMacros() { var currentWeightValid = validateInput(currentWeightInput, currentWeightError, 1, undefined, 'Current Weight'); var heightValid = validateInput(heightInput, heightError, 1, undefined, 'Height'); var ageValid = validateInput(ageInput, ageError, 1, undefined, 'Age'); var weightLossGoalValid = validateInput(weightLossGoalInput, weightLossGoalError, 0.1, 2, 'Weight Loss Goal'); if (!currentWeightValid || !heightValid || !ageValid || !weightLossGoalValid) { resetResults(); return; } var currentWeight = parseFloat(currentWeightInput.value); var height = parseFloat(heightInput.value); var age = parseInt(ageInput.value); var gender = genderSelect.value; var activityLevel = activityLevelSelect.value; var weightLossGoal = parseFloat(weightLossGoalInput.value); var bmr; if (gender === 'male') { bmr = (10 * currentWeight) + (6.25 * height) – (5 * age) + 5; } else { bmr = (10 * currentWeight) + (6.25 * height) – (5 * age) – 161; } var activityMultiplier; switch (activityLevel) { case 'sedentary': activityMultiplier = 1.2; break; case 'lightly_active': activityMultiplier = 1.375; break; case 'moderately_active': activityMultiplier = 1.55; break; case 'very_active': activityMultiplier = 1.725; break; case 'extra_active': activityMultiplier = 1.9; break; default: activityMultiplier = 1.2; } var tdee = bmr * activityMultiplier; var calorieDeficit = weightLossGoal * 7700 / 7; var targetCalories = tdee – calorieDeficit; if (targetCalories < 800) { // Minimum reasonable calorie intake targetCalories = 800; calorieDeficit = tdee – targetCalories; weightLossGoal = calorieDeficit * 7 / 7700; weightLossGoalInput.value = weightLossGoal.toFixed(1); document.getElementById('weightLossGoalError').textContent = 'Target calories set to minimum. Weight loss goal adjusted.'; } var proteinGrams, carbGrams, fatGrams; var proteinTargetPerKg = 1.8; // Default to a balanced protein intake proteinGrams = currentWeight * proteinTargetPerKg; var proteinCalories = proteinGrams * 4; var fatPercentage = 0.25; // Default to 25% fat var fatCalories = targetCalories * fatPercentage; fatGrams = fatCalories / 9; carbGrams = (targetCalories – proteinCalories – fatCalories) / 4; // Ensure macros are not negative proteinGrams = Math.max(0, proteinGrams); fatGrams = Math.max(0, fatGrams); carbGrams = Math.max(0, carbGrams); // Round to reasonable precision var roundedTargetCalories = Math.round(targetCalories); var roundedCalorieDeficit = Math.round(calorieDeficit); var roundedProteinGrams = Math.round(proteinGrams); var roundedCarbGrams = Math.round(carbGrams); var roundedFatGrams = Math.round(fatGrams); mainResultDiv.textContent = roundedTargetCalories + ' kcal'; targetTDEEDiv.textContent = Math.round(tdee); calorieDeficitDiv.textContent = roundedCalorieDeficit; proteinGramsDiv.textContent = roundedProteinGrams; carbGramsDiv.textContent = roundedCarbGrams; fatGramsDiv.textContent = roundedFatGrams; updateChart(roundedProteinGrams * 4, roundedCarbGrams * 4, roundedFatGrams * 9); } function resetResults() { mainResultDiv.textContent = '– kcal'; targetTDEEDiv.textContent = '–'; calorieDeficitDiv.textContent = '–'; proteinGramsDiv.textContent = '–'; carbGramsDiv.textContent = '–'; fatGramsDiv.textContent = '–'; if (macroChartContext) { macroChartContext.clearRect(0, 0, macroChartCanvas.width, macroChartCanvas.height); } } function resetCalculator() { currentWeightInput.value = 70; heightInput.value = 170; ageInput.value = 30; genderSelect.value = 'male'; activityLevelSelect.value = 'moderately_active'; weightLossGoalInput.value = 0.5; document.getElementById('currentWeightError').textContent = ''; document.getElementById('heightError').textContent = ''; document.getElementById('ageError').textContent = ''; document.getElementById('weightLossGoalError').textContent = ''; calculateMacros(); } function copyResults() { var tdee = targetTDEEDiv.textContent; var deficit = calorieDeficitDiv.textContent; var protein = proteinGramsDiv.textContent; var carbs = carbGramsDiv.textContent; var fat = fatGramsDiv.textContent; var totalCals = mainResultDiv.textContent.replace(' kcal', ''); var assumptions = "Current Weight: " + currentWeightInput.value + " kg\n"; assumptions += "Height: " + heightInput.value + " cm\n"; assumptions += "Age: " + ageInput.value + " years\n"; assumptions += "Gender: " + genderSelect.value + "\n"; assumptions += "Activity Level: " + activityLevelSelect.options[activityLevelSelect.selectedIndex].text + "\n"; assumptions += "Weight Loss Goal: " + weightLossGoalInput.value + " kg/week\n"; var textToCopy = "— Your Macro Targets for Weight Loss —\n\n"; textToCopy += "Target Daily Calories: " + totalCals + " kcal\n"; textToCopy += "Estimated TDEE (Maintenance Calories): " + tdee + " kcal/day\n"; textToCopy += "Required Calorie Deficit: " + deficit + " kcal/day\n\n"; textToCopy += "Macronutrient Breakdown:\n"; textToCopy += "Protein: " + protein + " grams/day\n"; textToCopy += "Carbohydrates: " + carbs + " grams/day\n"; textToCopy += "Fat: " + fat + " grams/day\n\n"; textToCopy += "— Key Assumptions —\n"; textToCopy += assumptions; var textarea = document.createElement('textarea'); textarea.value = textToCopy; textarea.style.position = 'fixed'; textarea.style.left = '-9999px'; document.body.appendChild(textarea); textarea.focus(); textarea.select(); try { var successful = document.execCommand('copy'); var msg = successful ? 'Results copied successfully!' : 'Failed to copy results.'; console.log(msg); // Optionally show a temporary success message to the user var copyButton = document.querySelector('button.copy'); var originalText = copyButton.textContent; copyButton.textContent = 'Copied!'; setTimeout(function() { copyButton.textContent = originalText; }, 2000); } catch (err) { console.error('Unable to copy results', err); } document.body.removeChild(textarea); } function updateChart(proteinCals, carbCals, fatCals) { if (macroChartInstance) { macroChartInstance.destroy(); } var totalCals = proteinCals + carbCals + fatCals; var proteinPerc = totalCals === 0 ? 0 : (proteinCals / totalCals) * 100; var carbPerc = totalCals === 0 ? 0 : (carbCals / totalCals) * 100; var fatPerc = totalCals === 0 ? 0 : (fatCals / totalCals) * 100; macroChartInstance = new Chart(macroChartContext, { type: 'doughnut', // Using doughnut for a pie-like chart data: { labels: ['Protein', 'Carbohydrates', 'Fat'], datasets: [{ data: [proteinPerc, carbPerc, fatPerc], backgroundColor: [ '#007bff', // Protein – Primary blue '#28a745', // Carbohydrates – Success green '#ffc107' // Fat – Warning yellow ], borderColor: '#fff', borderWidth: 2 }] }, options: { responsive: true, maintainAspectRatio: false, plugins: { legend: { position: 'bottom', }, tooltip: { callbacks: { label: function(context) { var label = context.label || ''; if (label) { label += ': '; } if (context.parsed !== null) { var value = context.parsed; label += value.toFixed(1) + '%'; } return label; } } } } } }); } // Initial calculation on load document.addEventListener('DOMContentLoaded', function() { // Need to load Chart.js library first if not using pure canvas drawing // For this requirement, we'll use pure canvas drawing logic within updateChart if Chart.js is not available. // However, a Chart.js instance is generally preferred for ease. // Assuming Chart.js is available globally. If not, pure drawing logic would replace updateChart. // Dummy Chart.js setup for example: In a real scenario, you'd include the Chart.js library. // For this specific output, we are asked to avoid external libraries and use pure canvas. // Let's replace Chart.js with pure canvas drawing. // — Pure Canvas Drawing Implementation — macroChartContext.clearRect(0, 0, macroChartCanvas.width, macroChartCanvas.height); // Clear initial state function drawPieSlice(ctx, centerX, centerY, radius, startAngle, endAngle, color) { ctx.fillStyle = color; ctx.beginPath(); ctx.moveTo(centerX, centerY); ctx.arc(centerX, centerY, radius, startAngle, endAngle); ctx.closePath(); ctx.fill(); } function drawDoughnutChart(data, colors, canvasId) { var canvas = document.getElementById(canvasId); var ctx = canvas.getContext('2d'); ctx.clearRect(0, 0, canvas.width, canvas.height); var totalValue = data.reduce(function(sum, value) { return sum + value; }, 0); if (totalValue === 0) return; // Don't draw if no data var centerX = canvas.width / 2; var centerY = canvas.height / 2; var radius = Math.min(centerX, centerY) * 0.8; // Make radius slightly smaller than half canvas size var innerRadius = radius * 0.6; // For doughnut effect var startAngle = 0; for (var i = 0; i < data.length; i++) { var sliceAngle = (data[i] / totalValue) * 2 * Math.PI; var endAngle = startAngle + sliceAngle; // Draw outer arc ctx.beginPath(); ctx.moveTo(centerX + radius * Math.cos(startAngle), centerY + radius * Math.sin(startAngle)); ctx.arc(centerX, centerY, radius, startAngle, endAngle); ctx.lineTo(centerX + innerRadius * Math.cos(endAngle), centerY + innerRadius * Math.sin(endAngle)); ctx.arc(centerX, centerY, innerRadius, endAngle, startAngle, true); ctx.closePath(); ctx.fillStyle = colors[i]; ctx.fill(); startAngle = endAngle; } // Draw center hole for doughnut effect ctx.beginPath(); ctx.arc(centerX, centerY, innerRadius, 0, 2 * Math.PI, false); ctx.fillStyle = '#fff'; // Match background ctx.fill(); // Add legend (simple text based) var legendHtml = '
'; var labels = ['Protein', 'Carbohydrates', 'Fat']; for (var i = 0; i < data.length; i++) { legendHtml += '
' + labels[i] + '
'; } legendHtml += '
'; var chartContainer = document.getElementById('macroChartSection'); var existingLegend = chartContainer.querySelector('.chart-legend'); if(existingLegend) existingLegend.remove(); var legendDiv = document.createElement('div'); legendDiv.className = 'chart-legend'; legendDiv.innerHTML = legendHtml; chartContainer.appendChild(legendDiv); } function updatePureCanvasChart(proteinCals, carbCals, fatCals) { var totalCals = proteinCals + carbCals + fatCals; var proteinPerc = totalCals === 0 ? 0 : (proteinCals / totalCals) * 100; var carbPerc = totalCals === 0 ? 0 : (carbCals / totalCals) * 100; var fatPerc = totalCals === 0 ? 0 : (fatCals / totalCals) * 100; var data = [proteinPerc, carbPerc, fatPerc]; var colors = ['#007bff', '#28a745', '#ffc107']; drawDoughnutChart(data, colors, 'macroChart'); } // Replace the call to updateChart with updatePureCanvasChart var originalUpdateChart = window.updateChart; window.updateChart = updatePureCanvasChart; // — End Pure Canvas Drawing Implementation — calculateMacros(); // Perform initial calculation // Add event listeners for real-time updates currentWeightInput.addEventListener('input', calculateMacros); heightInput.addEventListener('input', calculateMacros); ageInput.addEventListener('input', calculateMacros); genderSelect.addEventListener('change', calculateMacros); activityLevelSelect.addEventListener('change', calculateMacros); weightLossGoalInput.addEventListener('input', calculateMacros); // FAQ Toggling var faqItems = document.querySelectorAll('.faq-item .question'); faqItems.forEach(function(item) { item.addEventListener('click', function() { var faqContainer = this.closest('.faq-item'); faqContainer.classList.toggle('open'); }); }); });

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