Calorie Calculator for Bodybuilding Weight Gain
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Calorie Calculator for Bodybuilding Weight Gain
Your Weight Gain Calorie Targets
Target Daily Protein (g):
Target Daily Carbs (g):
Target Daily Fats (g):
Key Assumption: 1 kg of body weight is approximately 7700 calories.
How it's calculated: Your total daily energy expenditure (TDEE) is calculated by multiplying your Basal Metabolic Rate (BMR) by your activity multiplier. To gain weight, you need to consume more calories than your TDEE. We add a surplus based on your desired weekly gain. Protein, Carbs, and Fats are calculated using common bodybuilding ratios for muscle gain.
Macronutrient Distribution (Grams per Day)
| Metric |
Value |
Unit |
Notes |
Daily calorie and macronutrient targets for bodybuilding weight gain.
What is a Calorie Calculator for Bodybuilding Weight Gain?
A calorie calculator for bodybuilding weight gain is an essential tool designed specifically for individuals aiming to increase muscle mass and body weight through resistance training. It helps determine the precise number of daily calories and macronutrients (protein, carbohydrates, and fats) one needs to consume to achieve a sustainable and effective lean muscle gain. This calculator moves beyond general weight gain by focusing on the anabolic requirements of bodybuilding, ensuring that the weight gained is primarily muscle tissue rather than excess body fat.
Who should use it?
- Bodybuilders and strength athletes looking to enter a bulking phase.
- Individuals seeking to increase lean muscle mass.
- Anyone struggling to gain weight or muscle despite consistent training.
- Athletes needing to optimize their caloric intake for performance and recovery.
Common Misconceptions:
- "Just eat everything": While a calorie surplus is necessary, indiscriminate eating leads to excessive fat gain, which is counterproductive for bodybuilding aesthetics and performance.
- "More protein is always better": There's an optimal range for protein intake. Consuming far beyond what the body can utilize for muscle protein synthesis is inefficient and can displace other crucial macronutrients.
- "Cardio kills gains": Moderate cardio can be beneficial for cardiovascular health and recovery, but excessive amounts can create too large a calorie deficit, hindering weight gain.
Calculating the correct caloric intake for bodybuilding weight gain involves several steps, starting with estimating your energy expenditure and then adding a surplus for growth. The core principle is that to gain weight, your calorie intake must exceed your Total Daily Energy Expenditure (TDEE).
The process typically involves:
- Calculating Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest to maintain basic life functions. We use either the Revised Harris-Benedict equation or the Mifflin-St Jeor equation for this.
- Calculating Total Daily Energy Expenditure (TDEE): BMR is multiplied by an activity factor to account for calories burned through daily activities and exercise.
- Adding a Caloric Surplus: To gain weight, a surplus of calories is added to the TDEE. This surplus is often determined by the desired rate of weight gain.
- Distributing Macronutrients: Based on the target calorie intake, the macros are distributed using common bodybuilding recommendations.
BMR Formulas:
Revised Harris-Benedict Equation (1990):
For Men: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) - (5.677 × age in years)
For Women: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) - (4.330 × age in years)
Mifflin-St Jeor Equation (1990):
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
Total Daily Energy Expenditure (TDEE):
TDEE = BMR × Activity Factor
Target Calorie Intake for Weight Gain:
Weight Gain Calories = TDEE + Calorie Surplus
The calorie surplus is calculated based on the desired weight gain. Since 1 kg of body weight is roughly equivalent to 7700 calories:
Calorie Surplus Per Day = (Desired Weight Gain per Week [kg] × 7700) / 7 days
For example, a target of 0.25 kg/week requires a surplus of (0.25 * 7700) / 7 = 275 calories per day.
Macronutrient Distribution (Example Ratios for Muscle Gain):
- Protein: 1.6 - 2.2 grams per kg of body weight.
- Fats: 20-30% of total daily calories.
- Carbohydrates: Remaining calories after protein and fat are allocated.
Example Calculation: For a 1500-calorie surplus, 80kg individual aiming for 2g/kg protein and 25% fat:
- Protein: 80 kg * 2 g/kg = 160 g (160g * 4 cal/g = 640 calories)
- Fat: 1500 calories * 0.25 = 375 calories (375 cal / 9 cal/g ≈ 42 g)
- Carbs: (1500 - 640 - 375) calories = 485 calories (485 cal / 4 cal/g ≈ 121 g)
- Total Target Calories = TDEE + 1500 Surplus
Variables Table
| Variable |
Meaning |
Unit |
Typical Range / Values |
| BMR |
Basal Metabolic Rate |
Calories per day |
Depends on body composition, age, sex |
| TDEE |
Total Daily Energy Expenditure |
Calories per day |
BMR * Activity Factor |
| Activity Factor |
Multiplier for physical activity |
Unitless |
1.2 (Sedentary) - 1.9 (Extra Active) |
| Weight (kg) |
Body Weight |
kg |
Realistic weights for adults |
| Height (cm) |
Body Height |
cm |
Realistic heights for adults |
| Age |
Age in years |
Years |
Typically 18-80 |
| Gender |
Biological Sex |
N/A |
Male, Female |
| Weight Gain Target (kg/week) |
Desired rate of weight gain |
kg/week |
0.1 to 0.5 (recommended) |
| Calorie Surplus |
Extra calories for weight gain |
Calories per day |
Approx. 250-500 kcal for 0.25-0.5 kg/week |
| Protein |
Protein intake |
grams/day |
1.6 - 2.2 g/kg body weight |
| Carbohydrates |
Carbohydrate intake |
grams/day |
Remaining calories after protein/fat |
| Fats |
Fat intake |
grams/day |
20-30% of total calories |
| Calorie Equivalence |
Caloric value of macronutrients |
kcal/g |
Protein: 4, Carbs: 4, Fats: 9 |
| Weight Equivalence |
Caloric value of body mass |
kcal/kg |
Approx. 7700 kcal/kg |
Practical Examples of Using the Calorie Calculator
Let's illustrate with two common scenarios for individuals aiming for bodybuilding weight gain.
Example 1: The Intermediate Lifter Seeking Lean Gains
Scenario: Sarah is a 28-year-old female who has been training consistently for two years. She weighs 60 kg, is 165 cm tall, and considers herself moderately active (3-4 gym sessions per week). She wants to gain about 0.25 kg of lean mass per week.
Inputs:
- Activity Level: Moderately Active (1.55)
- BMR Method: Mifflin-St Jeor
- Gender: Female
- Weight: 60 kg
- Height: 165 cm
- Age: 28
- Desired Weight Gain: 0.25 kg/week
Calculation Breakdown:
- BMR (Mifflin-St Jeor, Female): (10 * 60) + (6.25 * 165) - (5 * 28) - 161 = 600 + 1031.25 - 140 - 161 = 1330.25 calories
- TDEE: 1330.25 * 1.55 = 2061.89 calories
- Calorie Surplus (for 0.25 kg/week): (0.25 * 7700) / 7 = 275 calories
- Target Daily Calories: 2061.89 + 275 = 2336.89 calories (rounded to 2337 calories)
- Target Protein: 60 kg * 2.0 g/kg = 120 g (480 calories)
- Target Fat: ~25% of 2337 calories = 584 calories / 9 cal/g = 65 g
- Target Carbs: (2337 - 480 - 584) calories / 4 cal/g = 1273 calories / 4 = 318 g
Interpretation: Sarah needs to consume approximately 2337 calories per day, with a focus on 120g protein, 65g fat, and 318g carbohydrates to support lean muscle growth without excessive fat accumulation.
Example 2: The Hardgainer bulking phase
Scenario: John is a 22-year-old male, 185 cm tall, weighing 75 kg. He trains intensely 5-6 days a week and has a physically demanding part-time job. He struggles to gain weight and wants to aim for a slightly higher surplus of 0.5 kg per week to maximize muscle gain during his bulking phase.
Inputs:
- Activity Level: Extra Active (1.9)
- BMR Method: Harris-Benedict (Revised)
- Gender: Male
- Weight: 75 kg
- Height: 185 cm
- Age: 22
- Desired Weight Gain: 0.5 kg/week
Calculation Breakdown:
- BMR (Harris-Benedict, Male): 88.362 + (13.397 * 75) + (4.799 * 185) - (5.677 * 22) = 88.362 + 1004.775 + 887.815 - 124.894 = 1856.058 calories
- TDEE: 1856.058 * 1.9 = 3526.51 calories
- Calorie Surplus (for 0.5 kg/week): (0.5 * 7700) / 7 = 550 calories
- Target Daily Calories: 3526.51 + 550 = 4076.51 calories (rounded to 4077 calories)
- Target Protein: 75 kg * 2.0 g/kg = 150 g (600 calories)
- Target Fat: ~25% of 4077 calories = 1019 calories / 9 cal/g = 113 g
- Target Carbs: (4077 - 600 - 1019) calories / 4 cal/g = 2458 calories / 4 = 615 g
Interpretation: John requires a substantial 4077 calories daily, emphasizing 150g protein, 113g fat, and 615g carbohydrates. This higher intake, coupled with his intense activity, is crucial for his goal of significant muscle gain.
How to Use This Calorie Calculator for Bodybuilding Weight Gain
Using our calorie calculator for bodybuilding weight gain is straightforward and designed to provide actionable insights quickly. Follow these steps:
- Select Activity Level: Honestly assess your weekly exercise routine and daily physical activity. Choose the option that best describes your lifestyle from the dropdown menu. This is crucial as it significantly impacts your TDEE.
- Choose BMR Method: While both Harris-Benedict and Mifflin-St Jeor are widely accepted, Mifflin-St Jeor is often considered slightly more accurate for the general population. You can experiment with both if you wish.
- Input Personal Details: Accurately enter your Gender, Weight (in kilograms), Height (in centimeters), and Age (in years). Precision here ensures the BMR calculation is as accurate as possible.
- Set Your Weight Gain Goal: Enter your desired weekly weight gain in kilograms. For most individuals focusing on lean muscle, 0.25 kg to 0.5 kg per week is a sustainable and effective target. Higher rates often lead to more fat gain.
- Click Calculate: Once all fields are filled, click the "Calculate Target Calories" button.
How to Read the Results:
- Main Result (Target Daily Calories): This is the highlighted, large number indicating your total daily calorie intake goal to achieve your desired weight gain.
- Intermediate Values: The calculator provides daily targets for Protein, Carbohydrates, and Fats in grams. These are crucial for muscle synthesis and energy.
- Table and Chart: The table offers a breakdown of all calculated metrics, including BMR, TDEE, and macros. The chart visually represents your daily macronutrient targets, making it easier to plan meals.
- Assumptions: Note the key assumption that 1 kg of body weight equates to 7700 calories. This is a standard energy conversion used in most weight management calculations.
Decision-Making Guidance:
- Adjust if Necessary: If you don't see results after 2-3 weeks (e.g., no weight gain, or excessive fat gain), adjust your daily calorie intake slightly (± 100-200 calories) and re-evaluate.
- Prioritize Protein: Ensure you consistently hit your protein target to maximize muscle protein synthesis.
- Nutrient Timing: While total daily intake is paramount, consider consuming a good portion of your carbohydrates and protein around your workouts.
- Listen to Your Body: Pay attention to energy levels, recovery, and body composition changes. The calculator provides a starting point; individual responses may vary.
Key Factors That Affect Calorie Calculator Results
While the calorie calculator for bodybuilding weight gain provides a data-driven estimate, several real-world factors can influence the actual results you achieve. Understanding these can help you fine-tune your approach:
- Metabolic Adaptation: Over time, your body can adapt to higher calorie intakes. Your metabolism might speed up slightly (adaptive thermogenesis), meaning you may need to incrementally increase calories to continue gaining weight.
- Body Composition: Individuals with more lean muscle mass generally have higher BMRs and TDEEs than those with less muscle, even at the same weight. The calculator uses weight and height, but body fat percentage also plays a role.
- Genetics: Your genetic predisposition significantly impacts how efficiently your body builds muscle, stores fat, and regulates metabolism. Some individuals are natural "hardgainers," while others gain muscle and fat more easily.
- Hormonal Factors: Hormones like testosterone, growth hormone, and insulin play critical roles in muscle growth and fat storage. Imbalances or variations can affect your results.
- Sleep Quality and Stress: Inadequate sleep and high stress levels can negatively impact recovery, hormone balance (e.g., increasing cortisol), and muscle protein synthesis, hindering weight gain progress.
- Nutrient Timing and Absorption: While total daily intake is king, the timing of meals and the bioavailability of nutrients can play a supporting role. Factors like digestive health can influence nutrient absorption.
- Training Intensity and Volume: The effectiveness of your resistance training program directly influences how your body utilizes the surplus calories. Insufficient stimulus means more calories are likely to be stored as fat.
- Digestion and Food Choices: The thermic effect of food (TEF) varies slightly by macronutrient (protein has the highest TEF). Also, the quality and digestibility of your food impact nutrient utilization.
Frequently Asked Questions (FAQ)
What is considered a "good" rate of weight gain for bodybuilding?
A generally recommended rate for lean muscle gain is between 0.25 kg and 0.5 kg (approximately 0.5 to 1 lb) per week. Gaining faster than this often results in a higher proportion of fat gain, which is undesirable for bodybuilding.
How many calories are in 1 kg of body weight?
It's estimated that 1 kg of body weight is equivalent to approximately 7700 calories. This figure is used to calculate the daily calorie surplus needed for a specific weight gain target.
Do I need to adjust my calories on rest days?
While some advanced strategies involve slight calorie cycling, for most individuals, maintaining a consistent daily calorie surplus is sufficient and simpler. Your TDEE accounts for your average activity, including training and rest. The key is consistency over the week.
How long should I stay in a calorie surplus for weight gain?
This depends on your goals. A "bulking" phase can last anywhere from 8 to 16 weeks, or until you reach a satisfactory level of muscle gain, after which you might transition to a maintenance or cutting phase.
What if I'm gaining too much fat?
If you're gaining weight faster than desired or notice significant fat accumulation, reduce your daily calorie intake by 100-200 calories. Also, ensure your training is challenging enough to stimulate muscle growth effectively. Review your macronutrient ratios, ensuring adequate protein intake.
Can I use this calculator if I'm vegetarian or vegan?
Yes, the calculator provides the total calorie and macronutrient targets. You will need to ensure you meet these targets through appropriate vegetarian or vegan food choices, paying close attention to protein sources.
How accurate are these BMR and TDEE calculations?
These formulas provide estimates. Individual metabolic rates can vary due to genetics, hormonal status, and other factors not captured by simple equations. It's best to use the calculator as a starting point and adjust based on your body's response.
Should I adjust calories based on my workout intensity?
The "Activity Level" multiplier in the calculator is designed to account for average weekly activity. For significant variations in daily activity (e.g., an extremely intense leg day vs. a light cardio session), slight adjustments might be considered, but consistency is usually more critical for long-term progress.
Is it possible to gain muscle and lose fat simultaneously?
This is challenging for most individuals, especially those who are already relatively lean. It's most feasible for beginners ("newbie gains"), individuals returning after a layoff, or those using performance-enhancing substances. For most, focusing on gaining muscle in a calorie surplus and then losing fat in a deficit is a more practical approach.
var activityLevelInput = document.getElementById('activityLevel');
var bmrMethodInput = document.getElementById('bmrMethod');
var genderInput = document.getElementById('gender');
var weightKgInput = document.getElementById('weightKg');
var heightCmInput = document.getElementById('heightCm');
var ageInput = document.getElementById('age');
var weightGainTargetKgPerWeekInput = document.getElementById('weightGainTargetKgPerWeek');
var activityLevelError = document.getElementById('activityLevelError');
var bmrMethodError = document.getElementById('bmrMethodError');
var genderError = document.getElementById('genderError');
var weightKgError = document.getElementById('weightKgError');
var heightCmError = document.getElementById('heightCmError');
var ageError = document.getElementById('ageError');
var weightGainTargetKgPerWeekError = document.getElementById('weightGainTargetKgPerWeekError');
var resultsContainer = document.getElementById('resultsContainer');
var mainResultDiv = document.getElementById('mainResult');
var targetProteinSpan = document.getElementById('targetProtein');
var targetCarbsSpan = document.getElementById('targetCarbs');
var targetFatsSpan = document.getElementById('targetFats');
var resultsTableBody = document.getElementById('resultsTableBody');
var macroChartCanvas = document.getElementById('macroChart');
var chartInstance = null;
var DEFAULT_WEIGHT_KG = 75;
var DEFAULT_HEIGHT_CM = 180;
var DEFAULT_AGE = 30;
var DEFAULT_WEIGHT_GAIN_TARGET = 0.25;
var DEFAULT_ACTIVITY_LEVEL = '1.55'; // Moderately Active
var DEFAULT_BMR_METHOD = 'mifflin-st-jeor';
var DEFAULT_GENDER = 'male';
function validateInput(value, elementId, errorElementId, min, max) {
var errorElement = document.getElementById(errorElementId);
errorElement.textContent = '';
var numValue = parseFloat(value);
if (isNaN(numValue)) {
errorElement.textContent = 'Please enter a valid number.';
return false;
}
if (value === '' || value === null) {
errorElement.textContent = 'This field is required.';
return false;
}
if (min !== undefined && numValue max) {
errorElement.textContent = 'Value cannot be greater than ' + max + '.';
return false;
}
return true;
}
function calculateBMR(weightKg, heightCm, age, gender, method) {
var bmr = 0;
if (method === 'harris-benedict') {
if (gender === 'male') {
bmr = 88.362 + (13.397 * weightKg) + (4.799 * heightCm) - (5.677 * age);
} else { // female
bmr = 447.593 + (9.247 * weightKg) + (3.098 * heightCm) - (4.330 * age);
}
} else { // mifflin-st-jeor (default)
if (gender === 'male') {
bmr = (10 * weightKg) + (6.25 * heightCm) - (5 * age) + 5;
} else { // female
bmr = (10 * weightKg) + (6.25 * heightCm) - (5 * age) - 161;
}
}
return bmr;
}
function calculateTDEE(bmr, activityFactor) {
return bmr * activityFactor;
}
function calculateCalories() {
var isValid = true;
// Validate inputs
if (!validateInput(weightKgInput.value, 'weightKg', 'weightKgError', 1)) isValid = false;
if (!validateInput(heightCmInput.value, 'heightCm', 'heightCmError', 1)) isValid = false;
if (!validateInput(ageInput.value, 'age', 'ageError', 1)) isValid = false;
if (!validateInput(weightGainTargetKgPerWeekInput.value, 'weightGainTargetKgPerWeek', 'weightGainTargetKgPerWeekError', 0.05, 1.0)) isValid = false;
if (!isValid) {
resultsContainer.style.display = 'none';
return;
}
var weightKg = parseFloat(weightKgInput.value);
var heightCm = parseFloat(heightCmInput.value);
var age = parseInt(ageInput.value);
var gender = genderInput.value;
var activityFactor = parseFloat(activityLevelInput.value);
var bmrMethod = bmrMethodInput.value;
var weightGainTargetKgPerWeek = parseFloat(weightGainTargetKgPerWeekInput.value);
var bmr = calculateBMR(weightKg, heightCm, age, gender, bmrMethod);
var tdee = calculateTDEE(bmr, activityFactor);
var caloriesPerKg = 7700;
var calorieSurplusPerDay = (weightGainTargetKgPerWeek * caloriesPerKg) / 7;
var targetCalories = tdee + calorieSurplusPerDay;
// Macronutrient Calculation
var proteinGramsPerKg = 2.0; // Common target for muscle gain
var targetProtein = weightKg * proteinGramsPerKg;
var proteinCalories = targetProtein * 4;
var fatPercentage = 0.25; // Common target for bodybuilding
var fatCalories = targetCalories * fatPercentage;
var targetFats = fatCalories / 9;
var carbCalories = targetCalories - proteinCalories - fatCalories;
var targetCarbs = carbCalories / 4;
// Ensure macros are not negative (can happen with very low calorie targets, though unlikely for weight gain)
targetProtein = Math.max(targetProtein, 0);
targetFats = Math.max(targetFats, 0);
targetCarbs = Math.max(targetCarbs, 0);
// Update results display
mainResultDiv.textContent = Math.round(targetCalories) + ' kcal';
targetProteinSpan.textContent = Math.round(targetProtein) + ' g';
targetCarbsSpan.textContent = Math.round(targetCarbs) + ' g';
targetFatsSpan.textContent = Math.round(targetFats) + ' g';
resultsTableBody.innerHTML = '';
resultsTableBody.innerHTML += '
| Basal Metabolic Rate (BMR) | ' + Math.round(bmr) + ' | kcal/day | ' + bmrMethod + ' |
';
resultsTableBody.innerHTML += '
| Total Daily Energy Expenditure (TDEE) | ' + Math.round(tdee) + ' | kcal/day | ' + Math.round(activityFactor * 100) / 100 + ' Activity Factor |
';
resultsTableBody.innerHTML += '
| Target Daily Calorie Surplus | ' + Math.round(calorieSurplusPerDay) + ' | kcal/day | For ' + weightGainTargetKgPerWeek + ' kg/week gain |
';
resultsTableBody.innerHTML += '
| Total Daily Calories | ' + Math.round(targetCalories) + ' | kcal/day | Goal: Weight Gain |
';
resultsTableBody.innerHTML += '
| Protein Target | ' + Math.round(targetProtein) + ' | grams/day | ~' + Math.round((targetProtein * 4) / targetCalories * 100) + '% of calories |
';
resultsTableBody.innerHTML += '
| Fat Target | ' + Math.round(targetFats) + ' | grams/day | ~' + Math.round((targetFats * 9) / targetCalories * 100) + '% of calories |
';
resultsTableBody.innerHTML += '
| Carbohydrate Target | ' + Math.round(targetCarbs) + ' | grams/day | ~' + Math.round((targetCarbs * 4) / targetCalories * 100) + '% of calories |
';
updateChart(targetProtein, targetCarbs, targetFats);
resultsContainer.style.display = 'block';
}
function resetCalculator() {
activityLevelInput.value = DEFAULT_ACTIVITY_LEVEL;
bmrMethodInput.value = DEFAULT_BMR_METHOD;
genderInput.value = DEFAULT_GENDER;
weightKgInput.value = DEFAULT_WEIGHT_KG;
heightCmInput.value = DEFAULT_HEIGHT_CM;
ageInput.value = DEFAULT_AGE;
weightGainTargetKgPerWeekInput.value = DEFAULT_WEIGHT_GAIN_TARGET;
// Clear errors
activityLevelError.textContent = '';
bmrMethodError.textContent = '';
genderError.textContent = '';
weightKgError.textContent = '';
heightCmError.textContent = '';
ageError.textContent = '';
weightGainTargetKgPerWeekError.textContent = '';
resultsContainer.style.display = 'none';
if (chartInstance) {
chartInstance.destroy();
chartInstance = null;
}
}
function copyResults() {
var resultText = "--- Bodybuilding Weight Gain Calculation Results ---\n\n";
resultText += "Target Daily Calories: " + mainResultDiv.textContent + "\n";
resultText += "Target Protein: " + targetProteinSpan.textContent + "\n";
resultText += "Target Carbohydrates: " + targetCarbsSpan.textContent + "\n";
resultText += "Target Fats: " + targetFatsSpan.textContent + "\n\n";
resultText += "Key Assumptions:\n";
resultText += " - 1 kg body weight = 7700 kcal\n";
resultText += " - Protein: " + proteinGramsPerKg + " g/kg body weight\n";
resultText += " - Fat: " + Math.round(fatPercentage * 100) + "% of total calories\n\n";
resultText += "Detailed Breakdown:\n";
var rows = resultsTableBody.getElementsByTagName('tr');
for (var i = 0; i < rows.length; i++) {
var cells = rows[i].getElementsByTagName('td');
if (cells.length === 4) {
resultText += cells[0].textContent + ": " + cells[1].textContent + " " + cells[2].textContent + " (" + cells[3].textContent + ")\n";
}
}
navigator.clipboard.writeText(resultText).then(function() {
// Optionally provide user feedback, e.g., change button text temporarily
var copyButton = document.querySelector('.copy-btn');
copyButton.textContent = 'Copied!';
setTimeout(function() {
copyButton.textContent = 'Copy Results';
}, 2000);
}).catch(function(err) {
console.error('Failed to copy results: ', err);
alert('Failed to copy results. Please copy manually.');
});
}
function updateChart(proteinGrams, carbsGrams, fatGrams) {
var ctx = macroChartCanvas.getContext('2d');
// Destroy previous chart instance if it exists
if (chartInstance) {
chartInstance.destroy();
}
chartInstance = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Protein', 'Carbohydrates', 'Fats'],
datasets: [{
label: 'Grams per Day',
data: [proteinGrams, carbsGrams, fatGrams],
backgroundColor: [
'rgba(54, 162, 235, 0.6)', // Blue for Protein
'rgba(255, 206, 86, 0.6)', // Yellow for Carbs
'rgba(255, 99, 132, 0.6)' // Red for Fats
],
borderColor: [
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(255, 99, 132, 1)'
],
borderWidth: 1
}]
},
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Grams'
}
}
},
plugins: {
legend: {
display: false // Hide legend as labels are on the bars
},
title: {
display: true,
text: 'Daily Macronutrient Targets'
}
}
}
});
}
// Initialize calculator on load
document.addEventListener('DOMContentLoaded', function() {
// Set default values and trigger calculation
resetCalculator(); // This also sets defaults and clears previous results
// Trigger calculation to show initial results based on defaults
setTimeout(calculateCalories, 100); // Small delay to ensure DOM is ready and default values are applied before calculation
});
// FAQ toggle functionality
var faqHeaders = document.querySelectorAll('.faq-section h3');
faqHeaders.forEach(function(header) {
header.addEventListener('click', function() {
var answer = this.nextElementSibling;
if (answer.style.display === 'block') {
answer.style.display = 'none';
} else {
answer.style.display = 'block';
}
});
});
// Need to include Chart.js library for the canvas chart.
// For a self-contained HTML file without external scripts,
// a pure SVG chart or canvas drawing would be needed.
// Since Chart.js is a common dependency, assume it might be available
// or would be included separately in a real-world scenario.
// For this specific output, we'll assume Chart.js is loaded externally
// or embed a basic Chart.js CDN link if absolute self-containment is critical.
// For production-ready, you'd host Chart.js locally.
// Adding CDN for Chart.js here for completeness within the single HTML.
var script = document.createElement('script');
script.src = 'https://cdn.jsdelivr.net/npm/chart.js@3.7.0/dist/chart.min.js';
document.head.appendChild(script);