Calories Diet Calculator for Weight Loss
Estimate your daily calorie needs to achieve your weight loss goals safely and effectively.
Weight Loss Calorie Calculator
Male
Female
Enter your current age in whole years.
Enter your current weight in kilograms.
Enter your height in centimeters.
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/sports & physical job)
Choose the option that best describes your daily physical activity.
Lose 0.5 kg/week (Small deficit)
Lose 1 kg/week (Moderate deficit)
Lose 0.75 kg/week (Balanced deficit)
Maintain Weight
Gain 0.5 kg/week (Small surplus)
Gain 1 kg/week (Moderate surplus)
Select your desired weekly weight change in kilograms.
Your Weight Loss Calorie Results
Enter your details above to see your personalized calorie targets.
Weekly Calorie Target Projection
This chart shows how your estimated daily calorie target might translate to weekly weight change over time, assuming consistency.
Basal Metabolic Rate (BMR) & Total Daily Energy Expenditure (TDEE) Breakdown
| Metric | Value | Unit | Description |
|---|---|---|---|
| Basal Metabolic Rate (BMR) | N/A | kcal/day | Calories burned at rest. |
| Activity Factor | N/A | – | Multiplier based on activity level. |
| Total Daily Energy Expenditure (TDEE) | N/A | kcal/day | Calories burned daily including activity. |
| Weight Change Adjustment | N/A | kcal/day | Calories adjusted for weight goal. |
What is a Calories Diet Calculator for Weight Loss?
{primary_keyword} is a crucial tool for anyone looking to manage their weight effectively. It helps individuals understand their body's unique energy requirements by calculating their Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). Based on these figures, and factoring in personal goals like weight loss, maintenance, or gain, the calculator provides a personalized daily calorie target. This estimate is essential for creating a sustainable eating plan that supports desired physiological changes without compromising health. Understanding your calorie needs is the foundational step in any successful weight management journey.
This calculator is ideal for individuals aiming for weight loss, weight gain, or weight maintenance. It's particularly useful for those who are new to tracking their intake or feel their current diet isn't yielding the desired results. It empowers users with data-driven insights, moving beyond guesswork. Common misconceptions include believing that drastically cutting calories is always the fastest or healthiest way to lose weight, or that all calories are equal regardless of their source. This calculator helps address these by providing a scientifically-backed target and highlighting the importance of personalized metrics like BMR and TDEE.
Calories Diet Calculator for Weight Loss Formula and Mathematical Explanation
The {primary_keyword} utilizes established formulas to provide accurate estimates. The primary components are the calculation of Basal Metabolic Rate (BMR) and then the Total Daily Energy Expenditure (TDEE), adjusted for specific weight goals.
Basal Metabolic Rate (BMR) Calculation
We use the Mifflin-St Jeor equation, which is widely considered one of the most accurate for estimating BMR:
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) Calculation
TDEE is calculated by multiplying the BMR by an activity factor that reflects the user's lifestyle:
TDEE = BMR × Activity Factor
The Activity Factors used are:
- Sedentary: 1.2
- Lightly active: 1.375
- Moderately active: 1.55
- Very active: 1.725
- Extra active: 1.9
Weight Goal Adjustment
To achieve a specific weight change, a calorie deficit or surplus is created. Approximately 3500 calories equate to 0.5 kg of body weight.
Target Daily Calories = TDEE + (Desired Weekly Weight Change × 1100)
Note: A positive Desired Weekly Weight Change (e.g., 0.5 kg/week for loss) results in a calorie deficit, while a negative value (e.g., -1 kg/week for gain) results in a calorie surplus. The 1100 factor comes from (3500 calories / 7 days) which is roughly 500 calories per day for 1 kg/week change. We adjust this to 1100 for a 0.5kg/week goal.
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Gender | Biological sex influencing metabolic rate | Categorical (Male/Female) | Male, Female |
| Age | Number of years lived | Years | 1 – 120 |
| Weight | Body mass | kg | 1 – 1000 |
| Height | Body stature | cm | 1 – 300 |
| Activity Factor | Multiplier for daily energy expenditure based on physical activity | Decimal (e.g., 1.2 to 1.9) | 1.2 – 1.9 |
| Desired Weekly Weight Change | Target rate of weight alteration per week | kg/week | -1 to 1 (approx.) |
| BMR | Calories burned at complete rest | kcal/day | ~1000 – 2500+ |
| TDEE | Total calories burned daily including activity | kcal/day | ~1200 – 4000+ |
| Target Daily Calories | Recommended daily calorie intake for goal | kcal/day | Variable based on TDEE and goal |
Practical Examples (Real-World Use Cases)
Example 1: Sarah, aiming for moderate weight loss
Inputs:
- Gender: Female
- Age: 32
- Weight: 68 kg
- Height: 165 cm
- Activity Level: Moderately active (1.55)
- Weight Loss Goal: Lose 0.75 kg/week
Calculation:
- BMR = (10 × 68) + (6.25 × 165) – (5 × 32) – 161 = 680 + 1031.25 – 160 – 161 = 1390.25 kcal/day
- TDEE = 1390.25 × 1.55 = 2154.89 kcal/day
- Target Daily Calories = 2155 + (0.75 × 1100) = 2155 + 825 = 2980 kcal/day Wait, this seems high for weight loss. Let's recheck the formula for weight loss. A deficit is needed.
- Target Daily Calories = TDEE – (0.75 * 1100) = 2155 – 825 = 1330 kcal/day.
Results:
- Estimated BMR: ~1390 kcal/day
- Estimated TDEE: ~2155 kcal/day
- Target Daily Calories for 0.75 kg/week loss: ~1330 kcal/day
Interpretation: Sarah needs to consume approximately 1330 calories per day to lose about 0.75 kg per week. This involves a significant deficit from her TDEE, so ensuring nutrient density is vital.
Example 2: Mark, aiming for maintenance
Inputs:
- Gender: Male
- Age: 45
- Weight: 85 kg
- Height: 180 cm
- Activity Level: Very active (1.725)
- Weight Loss Goal: Maintain Weight (0 kg/week)
Calculation:
- BMR = (10 × 85) + (6.25 × 180) – (5 × 45) + 5 = 850 + 1125 – 225 + 5 = 1755 kcal/day
- TDEE = 1755 × 1.725 = 3027.38 kcal/day
- Target Daily Calories = 3027 + (0 × 1100) = 3027 kcal/day
Results:
- Estimated BMR: ~1755 kcal/day
- Estimated TDEE: ~3027 kcal/day
- Target Daily Calories for Maintenance: ~3027 kcal/day
Interpretation: Mark needs to consume approximately 3027 calories per day to maintain his current weight, given his activity level. Consuming significantly less would lead to weight loss, while consuming more would lead to weight gain.
How to Use This Calories Diet Calculator for Weight Loss
Using our {primary_keyword} is straightforward and provides valuable insights into your personal energy needs.
- Enter Your Details: Accurately input your gender, age, weight (in kg), and height (in cm).
- Select Activity Level: Choose the option that best reflects your typical weekly physical activity. Be honest to get the most accurate TDEE estimate.
- Set Your Weight Goal: Specify whether you aim to lose weight (and at what rate), maintain your current weight, or gain weight.
- Calculate: Click the "Calculate Calories" button.
Reading Your Results:
- BMR (Basal Metabolic Rate): This is the minimum number of calories your body needs to perform basic life-sustaining functions at rest.
- TDEE (Total Daily Energy Expenditure): This is your estimated daily calorie burn, including your BMR and the calories you burn through all daily activities and exercise.
- Target Daily Calories: This is the adjusted calorie intake recommended to achieve your specific weight goal (loss, maintenance, or gain). For weight loss, this number will be lower than your TDEE; for gain, it will be higher.
- Projection Chart: Visualizes the potential impact of your target daily calories over a week.
- Breakdown Table: Provides a clear view of your BMR, TDEE, and the adjustment for your goal.
Decision-Making Guidance:
Use the Target Daily Calories as a guideline. Sustainable weight loss typically involves a deficit of 500-1000 calories per day for a loss of 0.5-1 kg per week. Drastic deficits can be unhealthy and unsustainable. If your target calories seem too low (e.g., below 1200 kcal/day), consult a healthcare professional or registered dietitian to ensure adequate nutrient intake and safety. For weight gain, a surplus of 250-500 calories per day is generally recommended.
Key Factors That Affect {primary_keyword} Results
While the calculator provides a solid estimate, several factors can influence your actual calorie needs and weight change:
- Metabolism Variations: Individual metabolic rates can differ due to genetics, hormonal balance, and body composition (muscle mass burns more calories than fat). The Mifflin-St Jeor equation is a good estimate, but personal variations exist.
- Hormonal Influences: Conditions like thyroid disorders (hypothyroidism or hyperthyroidism) can significantly impact metabolism and calorie requirements. Pregnancy and breastfeeding also drastically increase calorie needs.
- Body Composition: The calculator uses total weight, but the ratio of muscle to fat mass is critical. A more muscular individual will have a higher BMR than someone of the same weight with a higher body fat percentage.
- Age and Muscle Mass: As people age, muscle mass often declines, which can lower BMR. Maintaining muscle through strength training is key to keeping metabolism elevated.
- Nutrient Timing and Macronutrient Distribution: While total calorie intake is primary for weight change, the source of calories (protein, carbs, fats) and meal timing can affect satiety, hormonal responses, and metabolic efficiency. For example, protein has a higher thermic effect than fats or carbs.
- Medications: Certain medications can influence metabolism, appetite, and weight, potentially affecting calorie needs or making weight loss/gain more challenging.
- Sleep Quality and Stress Levels: Poor sleep and high stress can disrupt hormones like cortisol and ghrelin, influencing appetite, fat storage, and energy expenditure, indirectly affecting weight management.
- Digestive Efficiency: Although difficult to quantify in a simple calculator, individual digestive systems absorb nutrients differently, potentially leading to slight variations in utilized calories.
Frequently Asked Questions (FAQ)
How accurate is this calories diet calculator for weight loss?
This calculator uses scientifically validated formulas like Mifflin-St Jeor, which are among the most accurate for estimating BMR and TDEE. However, individual metabolisms vary, so results should be considered a strong starting point rather than an absolute figure. Consistent monitoring and adjustments based on your body's response are key.
Is a 0.5 kg or 1 kg per week weight loss goal healthy?
Yes, a weight loss of 0.5 kg to 1 kg per week is generally considered safe and sustainable for most individuals. It represents a calorie deficit of approximately 500 to 1000 calories per day. Faster rates may be possible initially but can be harder to maintain and may lead to muscle loss if not managed properly.
What if my calculated target calories seem too low or too high?
If your target calories are below 1200 kcal/day (for women) or 1500 kcal/day (for men), it might be difficult to get adequate nutrients. Consult a healthcare professional. If the target seems unusually high for weight loss, double-check your activity level input. Remember, these are estimates; adjust based on your body's feedback.
Do I need to track macronutrients (protein, carbs, fat) as well?
While total calorie intake is the primary driver for weight change, macronutrient balance is crucial for overall health, satiety, muscle preservation during weight loss, and performance. Once you have your target calories, distributing them among protein, carbohydrates, and fats according to dietary guidelines or personal preference is recommended.
Can I use this calculator if I am pregnant or breastfeeding?
No, this calculator is not suitable for pregnant or breastfeeding individuals. Calorie needs increase significantly during these periods, and specific nutritional guidance from a healthcare provider is essential.
How does activity level affect my calorie needs?
Activity level is a major factor. The more active you are, the higher your TDEE. A sedentary person burns far fewer calories daily than someone engaged in regular, intense exercise. The activity multiplier adjusts your BMR to account for this energy expenditure.
What is the difference between BMR and TDEE?
BMR is the calories your body burns at complete rest, essential for basic functions. TDEE includes BMR plus all calories burned through physical activity, digestion, and daily movement. TDEE is a more accurate reflection of your total daily calorie needs.
How quickly can I expect to see results?
If you consistently adhere to your calculated calorie target, you can expect to see changes in weight gradually. A loss of 0.5 kg per week means roughly 2 kg per month. Consistency and patience are vital for long-term success.
Related Tools and Internal Resources
- Calorie Diet Calculator – Our primary tool for estimating daily calorie needs.
- Macronutrient Calculator – Determine the optimal balance of protein, carbs, and fats for your goals.
- BMI Calculator – Understand your Body Mass Index and its implications.
- Water Intake Calculator – Calculate your recommended daily water consumption for optimal health.
- Guide to Fitness Tracking – Learn how to effectively monitor your physical activity and progress.
- Healthy Eating Strategies – Discover practical tips for building a balanced and nutritious diet.
' + targetCalories.toFixed(0) + ' kcal/day
';
resultsContent += 'This is your estimated daily calorie target to achieve your goal.
';
resultsContent += 'Your BMR: ' + bmr.toFixed(0) + ' kcal/day
';
resultsContent += 'Your TDEE: ' + tdee.toFixed(0) + ' kcal/day
';
resultsContent += 'Weight Goal Adjustment: ' + weightChangeAdjustment.toFixed(0) + ' kcal/day
';
document.getElementById("resultsContent").innerHTML = resultsContent;
// Update table
document.getElementById("bmrValue").textContent = bmr.toFixed(0);
document.getElementById("activityFactorValue").textContent = activityLevel;
document.getElementById("tdeeValue").textContent = tdee.toFixed(0);
document.getElementById("weightAdjustmentValue").textContent = weightChangeAdjustment.toFixed(0);
// Update Chart
updateChart(targetCalories, tdee, bmr);
}
function updateChart(targetCalories, tdee, bmr) {
var ctx = document.getElementById('calorieProjectionChart').getContext('2d');
// Calculate projected values for the week
var days = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
var weeklyTargets = [];
var weeklyTDEE = [];
var weeklyBMR = [];
for (var i = 0; i < days.length; i++) {
weeklyTargets.push(targetCalories);
weeklyTDEE.push(tdee);
weeklyBMR.push(bmr);
}
// Destroy previous chart instance if it exists
if (chartInstance) {
chartInstance.destroy();
}
chartInstance = new Chart(ctx, {
type: 'line',
data: {
labels: days,
datasets: [
{
label: 'Target Daily Calories',
data: weeklyTargets,
borderColor: '#004a99', // Primary color
backgroundColor: 'rgba(0, 74, 153, 0.1)',
fill: false,
tension: 0.1
},
{
label: 'Estimated TDEE',
data: weeklyTDEE,
borderColor: '#28a745', // Success color
backgroundColor: 'rgba(40, 167, 69, 0.1)',
fill: false,
tension: 0.1
},
{
label: 'BMR (Resting Calories)',
data: weeklyBMR,
borderColor: '#ffc107', // Warning color
backgroundColor: 'rgba(255, 193, 7, 0.1)',
fill: false,
tension: 0.1
}
]
},
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
y: {
beginAtZero: true,
title: {
display: true,
text: 'Calories (kcal)'
}
},
x: {
title: {
display: true,
text: 'Day of the Week'
}
}
},
plugins: {
legend: {
position: 'top',
},
title: {
display: true,
text: 'Projected Daily Calorie Needs vs. Target'
}
}
}
});
}
function clearErrors() {
var errorElements = document.querySelectorAll('.error-message');
for (var i = 0; i < errorElements.length; i++) {
errorElements[i].style.display = 'none';
errorElements[i].textContent = '';
}
var inputElements = document.querySelectorAll('.loan-calc-container input, .loan-calc-container select');
for (var i = 0; i < inputElements.length; i++) {
inputElements[i].classList.remove('input-error');
}
}
function displayError(id, message) {
var errorElement = document.getElementById(id + '-error');
if (errorElement) {
errorElement.textContent = message;
errorElement.style.display = 'block';
}
var inputElement = document.getElementById(id);
if (inputElement) {
inputElement.classList.add('input-error');
}
}
function resetForm() {
document.getElementById("gender").value = "male";
document.getElementById("age").value = "";
document.getElementById("weight").value = "";
document.getElementById("height").value = "";
document.getElementById("activityLevel").value = "1.2"; // Sedentary default
document.getElementById("goal").value = "0"; // Maintain weight default
document.getElementById("resultsContent").innerHTML = 'Enter your details above to see your personalized calorie targets.';
document.getElementById("bmrValue").textContent = "N/A";
document.getElementById("activityFactorValue").textContent = "N/A";
document.getElementById("tdeeValue").textContent = "N/A";
document.getElementById("weightAdjustmentValue").textContent = "N/A";
if (chartInstance) {
chartInstance.destroy();
chartInstance = null;
}
document.getElementById('calorieProjectionChart').getContext('2d').clearRect(0, 0, 1, 1); // Clear canvas if no chart
clearErrors();
}
function copyResults() {
var resultsText = "— Calorie Diet Calculator Results —\n\n";
var gender = document.getElementById("gender");
var ageInput = document.getElementById("age");
var weightInput = document.getElementById("weight");
var heightInput = document.getElementById("height");
var activityLevelSelect = document.getElementById("activityLevel");
var goalSelect = document.getElementById("goal");
resultsText += "Inputs:\n";
resultsText += "- Gender: " + gender.options[gender.selectedIndex].text + "\n";
resultsText += "- Age: " + (ageInput.value || 'N/A') + " years\n";
resultsText += "- Weight: " + (weightInput.value || 'N/A') + " kg\n";
resultsText += "- Height: " + (heightInput.value || 'N/A') + " cm\n";
resultsText += "- Activity Level: " + activityLevelSelect.options[activityLevelSelect.selectedIndex].text + "\n";
resultsText += "- Weight Goal: " + goalSelect.options[goalSelect.selectedIndex].text + "\n\n";
var primaryResultEl = document.querySelector("#resultsContent .primary-result");
var bmrValueEl = document.getElementById("bmrValue");
var tdeeValueEl = document.getElementById("tdeeValue");
var weightAdjustmentEl = document.getElementById("weightAdjustmentValue");
if (primaryResultEl) {
resultsText += "Primary Result:\n";
resultsText += "- Target Daily Calories: " + primaryResultEl.textContent.trim() + "\n\n";
}
resultsText += "Key Values:\n";
resultsText += "- BMR: " + (bmrValueEl.textContent === 'N/A' ? 'N/A' : bmrValueEl.textContent + ' kcal/day') + "\n";
resultsText += "- TDEE: " + (tdeeValueEl.textContent === 'N/A' ? 'N/A' : tdeeValueEl.textContent + ' kcal/day') + "\n";
resultsText += "- Weight Goal Adjustment: " + (weightAdjustmentEl.textContent === 'N/A' ? 'N/A' : weightAdjustmentEl.textContent + ' kcal/day') + "\n\n";
resultsText += "Key Assumptions:\n";
resultsText += "- Uses Mifflin-St Jeor equation for BMR.\n";
resultsText += "- Weight change assumes ~7700 kcal per kg of fat.\n";
resultsText += "- Results are estimates and individual needs may vary.\n";
// Use a temporary textarea to copy text
var textArea = document.createElement("textarea");
textArea.value = resultsText;
textArea.style.position = "fixed"; // Avoid scrolling to bottom
textArea.style.left = "-9999px";
document.body.appendChild(textArea);
textArea.focus();
textArea.select();
try {
var successful = document.execCommand('copy');
var msg = successful ? 'Results copied to clipboard!' : 'Copying failed!';
// Optionally show a temporary message to the user
console.log(msg);
// alert(msg); // Uncomment to show alert
} catch (err) {
console.error('Fallback: Oops, unable to copy', err);
// alert('Copying failed. Please copy manually.'); // Uncomment to show alert
}
document.body.removeChild(textArea);
}
// Initial calculation on load if defaults are set, or just display placeholder
document.addEventListener('DOMContentLoaded', function() {
// Optional: Call calculateCalories() here if you want initial calculation on page load
// calculateCalories();
// Add placeholder text for chart if needed, or just var it be empty until calculated
});
// Need Chart.js library, but per instructions, cannot use external libraries.
// Will implement a very basic SVG or Canvas approach if Chart.js is truly forbidden.
// *Correction*: Instruction says "No external chart libraries", implying native HTML Canvas is okay.
// Let's assume Chart.js is NOT allowed and implement a basic canvas drawing.
// Re-reading: "Native OR Pure SVG". Chart.js IS an external library.
// Implementing a basic native canvas chart.
function drawBasicChart(targetCalories, tdee, bmr) {
var canvas = document.getElementById('calorieProjectionChart');
var ctx = canvas.getContext('2d');
ctx.clearRect(0, 0, canvas.width, canvas.height); // Clear previous drawing
var canvasWidth = canvas.offsetWidth;
var canvasHeight = canvas.offsetHeight;
var padding = 40;
var chartAreaWidth = canvasWidth – 2 * padding;
var chartAreaHeight = canvasAreaHeight – 2 * padding;
// Find max value for scaling
var maxValue = Math.max(targetCalories, tdee, bmr) * 1.1; // Add some buffer
if (maxValue === 0) maxValue = 1000; // Default if no values
var scaleY = chartAreaHeight / maxValue;
// Draw axes
ctx.beginPath();
ctx.strokeStyle = '#ccc';
ctx.lineWidth = 1;
// Y-axis
ctx.moveTo(padding, padding);
ctx.lineTo(padding, canvasHeight – padding);
ctx.stroke();
// X-axis
ctx.moveTo(padding, canvasHeight – padding);
ctx.lineTo(canvasWidth – padding, canvasHeight – padding);
ctx.stroke();
// Draw labels for axes
ctx.fillStyle = '#555′;
ctx.font = '12px Arial';
ctx.textAlign = 'right';
ctx.fillText(maxValue.toFixed(0) + ' kcal', padding – 10, padding);
ctx.fillText('0 kcal', padding – 10, canvasHeight – padding);
ctx.textAlign = 'center';
ctx.fillText('Day of Week', canvasWidth / 2, canvasHeight – padding / 2);
ctx.save();
ctx.translate(padding / 2, (canvasHeight – padding) / 2);
ctx.rotate(-Math.PI / 2);
ctx.fillText('Calories (kcal)', 0, 0);
ctx.restore();
// Draw bars for each day
var days = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
var barWidth = chartAreaWidth / (days.length * 2); // Gap between bars
var spacing = chartAreaWidth / days.length;
ctx.lineWidth = 2;
// BMR Line
ctx.beginPath();
ctx.strokeStyle = '#ffc107'; // Warning color
ctx.lineWidth = 2;
for(var i = 0; i < days.length; i++) {
var xPos = padding + spacing * i;
var yPos = canvasHeight – padding – (bmr * scaleY);
if (i === 0) {
ctx.moveTo(xPos, yPos);
} else {
ctx.lineTo(xPos, yPos);
}
}
ctx.stroke();
// TDEE Line
ctx.beginPath();
ctx.strokeStyle = '#28a745'; // Success color
ctx.lineWidth = 2;
for(var i = 0; i < days.length; i++) {
var xPos = padding + spacing * i;
var yPos = canvasHeight – padding – (tdee * scaleY);
if (i === 0) {
ctx.moveTo(xPos, yPos);
} else {
ctx.lineTo(xPos, yPos);
}
}
ctx.stroke();
// Target Calories Line
ctx.beginPath();
ctx.strokeStyle = '#004a99'; // Primary color
ctx.lineWidth = 2;
for(var i = 0; i < days.length; i++) {
var xPos = padding + spacing * i;
var yPos = canvasHeight – padding – (targetCalories * scaleY);
if (i === 0) {
ctx.moveTo(xPos, yPos);
} else {
ctx.lineTo(xPos, yPos);
}
}
ctx.stroke();
// Draw day labels
ctx.fillStyle = '#555';
ctx.font = '12px Arial';
ctx.textAlign = 'center';
for(var i = 0; i < days.length; i++) {
ctx.fillText(days[i], padding + spacing * i, canvasHeight – padding + 15);
}
// Draw legend manually
ctx.font = '14px Arial';
ctx.textAlign = 'left';
var legendY = padding + 20;
var legendSpacing = 20;
// BMR Legend
ctx.fillStyle = '#ffc107';
ctx.fillRect(padding, legendY, 15, 10);
ctx.fillStyle = '#333';
ctx.fillText('BMR', padding + 25, legendY + 10);
legendY += legendSpacing;
// TDEE Legend
ctx.fillStyle = '#28a745';
ctx.fillRect(padding, legendY, 15, 10);
ctx.fillStyle = '#333';
ctx.fillText('TDEE', padding + 25, legendY + 10);
legendY += legendSpacing;
// Target Calories Legend
ctx.fillStyle = '#004a99';
ctx.fillRect(padding, legendY, 15, 10);
ctx.fillStyle = '#333';
ctx.fillText('Target Calories', padding + 25, legendY + 10);
}
// Override the chart update function to use the basic canvas drawing
function updateChart(targetCalories, tdee, bmr) {
drawBasicChart(targetCalories, tdee, bmr);
}
// Trigger initial calculation if default values are set or if the form should pre-fill
document.addEventListener('DOMContentLoaded', function() {
// Optional: Set default values for a smoother experience
// document.getElementById("gender").value = "female";
// document.getElementById("age").value = "30";
// document.getElementById("weight").value = "65";
// document.getElementById("height").value = "165";
// document.getElementById("activityLevel").value = "1.375"; // Lightly active
// document.getElementById("goal").value = "0.5"; // Lose 0.5 kg/week
// calculateCalories(); // Uncomment to run calculation on load
});