Understand your weight loss journey and track your progress with precision.
Weight Loss Progress Tracker
Enter your weight when you started. (e.g., 75 kg)
Enter your current weight. (e.g., 70 kg)
Enter your desired weight goal. (e.g., 65 kg)
Kilograms (kg)
Pounds (lbs)
Select your preferred unit of measurement.
Time elapsed since starting weight (in weeks). (e.g., 4 weeks)
Your Weight Loss Summary
Total Weight Lost—
Weight Lost This Period—
Remaining Weight to Lose—
Average Weekly Loss—
Estimated Time to Target—
How it's Calculated:
Total Weight Lost = Starting Weight – Current Weight. Weight Lost This Period is the same as Total Weight Lost. Remaining Weight to Lose = Current Weight – Target Weight (if positive) or Target Weight – Current Weight (if negative). Average Weekly Loss = Total Weight Lost / Time Period. Estimated Time to Target = Remaining Weight to Lose / Average Weekly Loss (if Average Weekly Loss is positive and > 0).
Weight Loss Progression Chart
Weight Over Time Visualization
Weight Loss Data Table
Weight Loss Milestones
Milestone
Weight ({currentUnitDisplay})
Change ({currentUnitDisplay})
Starting Weight
—
—
Current Weight
—
—
Target Weight
—
—
What is a Weight Loss Calculator by Weight?
A Weight Loss Calculator by Weight is a specialized online tool designed to help individuals track, estimate, and visualize their weight loss progress based on their starting weight, current weight, target weight, and the time elapsed. Unlike generic calculators, this tool focuses specifically on the metrics derived from weight measurements, providing clear insights into how much weight has been lost, how much is left to lose, and the rate of weight loss over a given period. It serves as a motivational tool and an analytical aid for anyone committed to a weight management journey.
This calculator is ideal for anyone actively trying to lose weight, maintain a healthy weight, or simply monitor changes in their body mass over time. Whether you're following a specific diet plan, an exercise regimen, or seeking professional guidance, understanding your weight loss trajectory is crucial. It helps in adjusting strategies, celebrating milestones, and staying accountable.
A common misconception is that weight loss calculators are only for people trying to lose a significant amount of weight. In reality, they are also valuable for those aiming for modest changes, athletes managing their weight class, or individuals focusing on body recomposition. Another misconception is that the calculator predicts future success with absolute certainty; it provides estimations based on current trends, but actual results can vary due to numerous biological and lifestyle factors.
Weight Loss Calculator by Weight Formula and Mathematical Explanation
The core of the Weight Loss Calculator by Weight relies on simple arithmetic operations to quantify changes and project trends. The primary goal is to translate raw weight data into meaningful progress indicators.
Derivation of Key Metrics:
1. Total Weight Lost: This is the most straightforward calculation, representing the absolute difference between the initial weight and the current weight.
Formula: Total Weight Lost = Starting Weight - Current Weight
2. Weight Lost This Period: For this specific calculator, "This Period" refers to the entire duration from the starting weight to the current weight. Therefore, it is identical to the Total Weight Lost.
Formula: Weight Lost This Period = Total Weight Lost
3. Remaining Weight to Lose: This metric indicates how much more weight needs to be shed to reach the target weight. It's calculated as the difference between the current weight and the target weight.
Formula: Remaining Weight to Lose = Current Weight - Target Weight
*Note: A negative result here implies the target weight has been surpassed.
4. Average Weekly Loss: This calculates the rate at which weight is being lost per week, providing an average trendline.
Formula: Average Weekly Loss = Total Weight Lost / Time Period (in weeks)
*Note: This calculation assumes a consistent loss rate. A positive Average Weekly Loss indicates weight loss; a negative value indicates weight gain.
5. Estimated Time to Target: This projection estimates how long it will take to reach the target weight, assuming the current rate of weight loss continues.
Formula: Estimated Time to Target = Remaining Weight to Lose / Average Weekly Loss
*Note: This calculation is only meaningful if Remaining Weight to Lose is positive and Average Weekly Loss is positive and greater than zero. If Average Weekly Loss is zero or negative, reaching the target at this rate is impossible or already achieved.
Variables Table:
Variables Used in Weight Loss Calculation
Variable
Meaning
Unit
Typical Range
Starting Weight
Weight at the beginning of the tracking period.
kg or lbs
1 – 500+
Current Weight
Weight measured at the present time.
kg or lbs
1 – 500+
Target Weight
Desired weight goal.
kg or lbs
1 – 500+
Time Period
Duration in weeks since starting weight.
Weeks
0.1 – 100+
Total Weight Lost
Difference between starting and current weight.
kg or lbs
Varies
Weight Lost This Period
Same as Total Weight Lost for this tracker.
kg or lbs
Varies
Remaining Weight to Lose
Difference between current and target weight.
kg or lbs
Varies
Average Weekly Loss
Rate of weight loss per week.
kg/week or lbs/week
Varies
Estimated Time to Target
Projected time to reach target weight.
Weeks
Varies
Practical Examples (Real-World Use Cases)
Understanding the practical application of a Weight Loss Calculator by Weight can highlight its utility. Here are a couple of scenarios:
Example 1: Consistent Weight Loss
Scenario: Sarah started her fitness journey 8 weeks ago. Her initial weight was 80 kg. Today, her current weight is 74 kg. Her target weight is 68 kg.
Inputs:
Starting Weight: 80 kg
Current Weight: 74 kg
Target Weight: 68 kg
Time Period: 8 weeks
Weight Unit: kg
Calculated Results:
Total Weight Lost: 80 kg – 74 kg = 6 kg
Weight Lost This Period: 6 kg
Remaining Weight to Lose: 74 kg – 68 kg = 6 kg
Average Weekly Loss: 6 kg / 8 weeks = 0.75 kg/week
Estimated Time to Target: 6 kg / 0.75 kg/week = 8 weeks
Interpretation: Sarah has successfully lost 6 kg in 8 weeks, averaging 0.75 kg per week. At this rate, she is projected to reach her target weight of 68 kg in another 8 weeks, provided she maintains her current habits. This indicates a healthy and consistent weight loss pace.
Example 2: Weight Gain and Re-evaluation
Scenario: John aimed to reach 90 kg, starting from 95 kg six weeks ago. However, due to recent lifestyle changes, his current weight is 93 kg.
Estimated Time to Target: 3 lbs / 0.33 lbs/week = 9.09 weeks
Interpretation: John has experienced a slight weight loss of 2 lbs over 6 weeks, averaging about 0.33 lbs per week. While he is moving towards his goal, the rate is slower than perhaps intended. He still has 3 lbs to lose and is estimated to reach his target in about 9 more weeks if this trend continues. This situation might prompt John to re-evaluate his diet and exercise plan to accelerate his progress.
How to Use This Weight Loss Calculator by Weight
Using the Weight Loss Calculator by Weight is straightforward and designed to provide immediate feedback on your progress. Follow these simple steps:
Enter Starting Weight: Input the weight (in your chosen unit, kg or lbs) from when you began your weight loss journey or the period you wish to track.
Enter Current Weight: Accurately record your current weight in the same unit. Ensure consistency in measurement times (e.g., morning, after using the restroom, before eating).
Enter Target Weight: Specify your desired weight goal. This helps calculate how much more weight you need to lose.
Select Weight Unit: Choose whether your measurements are in Kilograms (kg) or Pounds (lbs). This ensures the calculations are accurate for your context.
Enter Time Period: Input the duration in weeks that has passed since you recorded your starting weight.
Click 'Calculate Progress': Once all fields are populated, click the button. The calculator will instantly display your key weight loss metrics.
How to Read Results:
Total Weight Lost: Shows the cumulative weight reduction. A positive number indicates progress.
Weight Lost This Period: Confirms the amount lost in the timeframe specified.
Remaining Weight to Lose: Indicates the difference between your current and target weight. A positive number means you still need to lose weight; a negative number means you've reached or exceeded your target.
Average Weekly Loss: Provides insight into your progress rate. A higher positive number generally signifies faster progress.
Estimated Time to Target: Offers a projection based on your current loss rate. Use this as a guide, understanding that actual timelines can vary.
Decision-Making Guidance:
Use the results to make informed decisions about your weight management strategy. If your average weekly loss is significantly higher than 1-2 lbs (or 0.5-1 kg), consider if the loss is sustainable and healthy. If your average weekly loss is very low or negative, it might be time to reassess your diet, exercise, or other lifestyle factors. The 'Estimated Time to Target' can help you set realistic expectations and stay motivated.
Key Factors That Affect Weight Loss Calculator Results
While the Weight Loss Calculator by Weight provides valuable insights based on inputted numbers, several real-world factors can influence actual weight loss and affect the accuracy of projections. Understanding these nuances is crucial for a holistic approach to weight management.
Metabolic Rate:
Each individual has a unique Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). Factors like age, sex, muscle mass, and genetics significantly impact how many calories your body burns at rest and during activity. A higher metabolic rate can lead to faster weight loss, making the calculator's projections potentially shorter than reality if the baseline metabolism is underestimated.
Caloric Deficit and Intake:
Weight loss fundamentally occurs when you consume fewer calories than you expend. The calculator assumes a consistent *implied* caloric deficit based on weight change. However, fluctuations in dietary intake and adherence to a specific caloric goal directly determine the actual rate of loss. Inconsistent eating habits can lead to unpredictable weight fluctuations that the calculator won't capture without updated inputs.
Physical Activity and Exercise Intensity:
The type, frequency, and intensity of exercise play a critical role. Regular, vigorous physical activity increases calorie expenditure, potentially accelerating weight loss beyond what might be predicted solely from dietary changes. Conversely, a lack of activity can slow progress. The calculator does not factor in exercise directly but relies on the resulting weight change.
Muscle Mass vs. Fat Mass:
Weight is not solely composed of fat. Muscle is denser than fat, meaning individuals may lose fat but gain muscle, resulting in minimal change or even an increase in total weight. The calculator measures total body weight change, not body composition. Therefore, someone gaining muscle while losing fat might see less impressive numbers on the calculator despite improving their health and body shape.
Water Retention and Fluctuations:
Body weight can fluctuate significantly day-to-day due to water retention influenced by sodium intake, hydration levels, hormonal changes (especially in women), and intense exercise. These short-term water weight shifts can temporarily mask fat loss or create misleading spikes, making the calculated average weekly loss a more reliable indicator over time than daily readings.
Sleep Quality and Stress Levels:
Inadequate sleep and high stress levels can disrupt hormones like cortisol and ghrelin, which regulate appetite and fat storage. Poor sleep and chronic stress can increase cravings, hinder recovery from exercise, and promote fat storage, thereby slowing down or even reversing weight loss progress. These physiological responses are not directly inputted into the calculator but can significantly impact the results.
Hormonal Factors and Medical Conditions:
Underlying medical conditions such as hypothyroidism, PCOS, or insulin resistance can affect metabolism and weight management. Certain medications can also cause weight gain or hinder weight loss. If such conditions are present, the weight loss journey might be more challenging, and the calculator's projections may need to be adjusted based on medical advice.
Frequently Asked Questions (FAQ)
Q1: How accurate is the Weight Loss Calculator by Weight?
A1: The calculator provides accurate calculations based on the numbers you input. However, it estimates future progress based on current trends. Actual weight loss can vary due to metabolism, diet adherence, exercise, and other physiological factors.
Q2: What is a healthy rate of weight loss?
A2: Generally, a healthy and sustainable rate of weight loss is considered to be 1-2 pounds (about 0.5-1 kg) per week. The calculator helps you see if you are within this range.
Q3: My average weekly loss is negative. What does this mean?
A3: A negative average weekly loss means you have gained weight since your starting point. It indicates that, on average, your current weight is higher than your starting weight.
Q4: Can I use this calculator if I'm trying to gain weight?
A4: While designed for weight loss, you could technically input numbers to track weight gain by setting a higher target weight than your current weight. However, the terminology ("Weight Lost") might be confusing. For weight gain, a different calculator focusing on 'Weight Gained' would be more appropriate.
Q5: Should I update my 'Current Weight' daily?
A5: Daily updates can show short-term fluctuations, which might be demotivating. It's often more beneficial to update your current weight weekly or bi-weekly to see a more stable trendline and rely on the 'Average Weekly Loss' for a clearer picture.
Q6: What if my 'Estimated Time to Target' is very long?
A6: A long estimated time might suggest that your current rate of weight loss is slow relative to your goal. This could be an opportunity to review your diet and exercise plan with a healthcare professional or nutritionist to see if adjustments can be made to accelerate progress safely.
Q7: Does the calculator account for muscle gain?
A7: No, the calculator only tracks total body weight. It does not differentiate between fat loss and muscle gain. If you are strength training, you might gain muscle while losing fat, which could result in less change on the scale than expected, even if your body composition is improving.
Q8: How often should I recalibrate my target weight?
A8: Your target weight might need adjustment as you progress. As you lose weight, your metabolism can change, and your body composition evolves. It's advisable to reassess your goals periodically, especially after reaching significant milestones or if your lifestyle circumstances change.
Related Tools and Internal Resources
BMI CalculatorCalculate your Body Mass Index (BMI) to understand if your weight is within a healthy range for your height.
Calorie CalculatorEstimate your daily calorie needs based on your BMR, activity level, and weight goals. Essential for creating a deficit.
Macronutrient Ratio CalculatorDetermine the optimal balance of carbohydrates, proteins, and fats for your diet based on your goals.
Healthy Eating TipsDiscover practical advice and strategies for adopting a balanced and nutritious diet to support your weight management.
Effective Exercises for Weight LossExplore different types of exercises and workout plans that can help maximize calorie burn and promote fat loss.
Weight Loss Journey TrackerA comprehensive tool to log your daily meals, workouts, and measurements for a detailed overview of your progress.
var weightUnitDisplay = 'kg'; // Default display unit
function validateInput(id, errorId, min, max, allowEmpty) {
var input = document.getElementById(id);
var errorElement = document.getElementById(errorId);
var value = parseFloat(input.value);
var isValid = true;
errorElement.textContent = "; // Clear previous error
if (isNaN(value)) {
if (!allowEmpty) {
errorElement.textContent = 'Please enter a valid number.';
isValid = false;
}
} else {
if (value 0
errorElement.textContent = 'Value cannot be negative.';
isValid = false;
} else if (id === 'timePeriod' && value <= 0) {
errorElement.textContent = 'Time period must be positive.';
isValid = false;
} else if (value max) {
errorElement.textContent = 'Value is too high.';
isValid = false;
}
}
input.style.borderColor = isValid ? " : 'red';
return isValid;
}
function updateUnitDisplay() {
weightUnitDisplay = document.getElementById('weightUnit').value;
document.getElementById('initialWeight').placeholder = `e.g., 75 ${weightUnitDisplay}`;
document.getElementById('currentWeight').placeholder = `e.g., 70 ${weightUnitDisplay}`;
document.getElementById('targetWeight').placeholder = `e.g., 65 ${weightUnitDisplay}`;
document.getElementById('tableStartWeight').parentNode.cells[1].textContent = `Starting Weight (${weightUnitDisplay})`;
document.getElementById('tableCurrentWeight').parentNode.cells[1].textContent = `Current Weight (${weightUnitDisplay})`;
document.getElementById('tableTargetWeight').parentNode.cells[1].textContent = `Target Weight (${weightUnitDisplay})`;
document.getElementById('tableWeightLostPeriod').parentNode.cells[2].textContent = `Change (${weightUnitDisplay})`;
document.getElementById('tableRemainingWeight').parentNode.cells[2].textContent = `Change (${weightUnitDisplay})`;
}
var weightLossChartInstance = null; // Global variable to hold chart instance
function calculateWeightLoss() {
var initialWeight = parseFloat(document.getElementById('initialWeight').value);
var currentWeight = parseFloat(document.getElementById('currentWeight').value);
var targetWeight = parseFloat(document.getElementById('targetWeight').value);
var timePeriod = parseFloat(document.getElementById('timePeriod').value);
var weightUnit = document.getElementById('weightUnit').value;
// Validation
var allValid = true;
allValid = validateInput('initialWeight', 'initialWeightError', 0, 1000) && allValid;
allValid = validateInput('currentWeight', 'currentWeightError', 0, 1000) && allValid;
allValid = validateInput('targetWeight', 'targetWeightError', 0, 1000) && allValid;
allValid = validateInput('timePeriod', 'timePeriodError', 0.1, 500) && allValid; // Allow time period > 0
if (!allValid) {
document.getElementById('totalWeightLost').textContent = '–';
document.getElementById('weightLostThisPeriod').textContent = '–';
document.getElementById('remainingWeightToLose').textContent = '–';
document.getElementById('averageWeeklyLoss').textContent = '–';
document.getElementById('estimatedTimeToTarget').textContent = '–';
// Clear table
document.getElementById('tableStartWeight').textContent = '–';
document.getElementById('tableCurrentWeight').textContent = '–';
document.getElementById('tableTargetWeight').textContent = '–';
document.getElementById('tableWeightLostPeriod').textContent = '–';
document.getElementById('tableRemainingWeight').textContent = '–';
return;
}
// Calculations
var totalWeightLost = initialWeight – currentWeight;
var weightLostThisPeriod = totalWeightLost; // Same as total for this calculator
var remainingWeightToLose = currentWeight – targetWeight;
var averageWeeklyLoss = 0;
if (timePeriod > 0) {
averageWeeklyLoss = totalWeightLost / timePeriod;
}
var estimatedTimeToTarget = '–';
if (averageWeeklyLoss > 0 && remainingWeightToLose > 0) {
estimatedTimeToTarget = (remainingWeightToLose / averageWeeklyLoss).toFixed(2) + ' weeks';
} else if (remainingWeightToLose <= 0) {
estimatedTimeToTarget = 'Target Achieved';
} else {
estimatedTimeToTarget = 'N/A';
}
// Display Results
var unitSuffix = weightUnit;
document.getElementById('totalWeightLost').textContent = totalWeightLost.toFixed(2) + ' ' + unitSuffix;
document.getElementById('weightLostThisPeriod').textContent = weightLostThisPeriod.toFixed(2) + ' ' + unitSuffix;
document.getElementById('remainingWeightToLose').textContent = remainingWeightToLose.toFixed(2) + ' ' + unitSuffix;
document.getElementById('averageWeeklyLoss').textContent = averageWeeklyLoss.toFixed(2) + ' / ' + unitSuffix + '/week';
document.getElementById('estimatedTimeToTarget').textContent = estimatedTimeToTarget;
// Update Table
document.getElementById('tableStartWeight').textContent = initialWeight.toFixed(2);
document.getElementById('tableCurrentWeight').textContent = currentWeight.toFixed(2);
document.getElementById('tableTargetWeight').textContent = targetWeight.toFixed(2);
document.getElementById('tableWeightLostPeriod').textContent = weightLostThisPeriod.toFixed(2);
document.getElementById('tableRemainingWeight').textContent = remainingWeightToLose.toFixed(2);
// Update chart data
updateChart(initialWeight, currentWeight, targetWeight, timePeriod, unitSuffix);
}
function resetCalculator() {
document.getElementById('initialWeight').value = '75';
document.getElementById('currentWeight').value = '70';
document.getElementById('targetWeight').value = '65';
document.getElementById('timePeriod').value = '4';
document.getElementById('weightUnit').value = 'kg';
document.getElementById('initialWeightError').textContent = '';
document.getElementById('currentWeightError').textContent = '';
document.getElementById('targetWeightError').textContent = '';
document.getElementById('timePeriodError').textContent = '';
document.getElementById('initialWeight').style.borderColor = '';
document.getElementById('currentWeight').style.borderColor = '';
document.getElementById('targetWeight').style.borderColor = '';
document.getElementById('timePeriod').style.borderColor = '';
updateUnitDisplay();
calculateWeightLoss(); // Recalculate with default values
}
function copyResults() {
var totalWeightLost = document.getElementById('totalWeightLost').textContent;
var weightLostThisPeriod = document.getElementById('weightLostThisPeriod').textContent;
var remainingWeightToLose = document.getElementById('remainingWeightToLose').textContent;
var averageWeeklyLoss = document.getElementById('averageWeeklyLoss').textContent;
var estimatedTimeToTarget = document.getElementById('estimatedTimeToTarget').textContent;
var initialWeight = document.getElementById('initialWeight').value;
var currentWeight = document.getElementById('currentWeight').value;
var targetWeight = document.getElementById('targetWeight').value;
var timePeriod = document.getElementById('timePeriod').value;
var weightUnit = document.getElementById('weightUnit').value;
var resultsText = "— Weight Loss Summary —\n\n";
resultsText += "Key Inputs:\n";
resultsText += " – Starting Weight: " + initialWeight + " " + weightUnit + "\n";
resultsText += " – Current Weight: " + currentWeight + " " + weightUnit + "\n";
resultsText += " – Target Weight: " + targetWeight + " " + weightUnit + "\n";
resultsText += " – Time Period: " + timePeriod + " weeks\n\n";
resultsText += "Calculated Metrics:\n";
resultsText += " – Total Weight Lost: " + totalWeightLost + "\n";
resultsText += " – Weight Lost This Period: " + weightLostThisPeriod + "\n";
resultsText += " – Remaining Weight to Lose: " + remainingWeightToLose + "\n";
resultsText += " – Average Weekly Loss: " + averageWeeklyLoss + "\n";
resultsText += " – Estimated Time to Target: " + estimatedTimeToTarget + "\n";
// Use a temporary textarea to copy to clipboard
var textArea = document.createElement("textarea");
textArea.value = resultsText;
textArea.style.position = "fixed"; // Avoid scrolling to bottom of page in MS Edge.
textArea.style.top = "0";
textArea.style.left = "0";
document.body.appendChild(textArea);
textArea.focus();
textArea.select();
try {
var successful = document.execCommand('copy');
var msg = successful ? 'Results copied to clipboard!' : 'Failed to copy results.';
// Optionally show a temporary message to the user
alert(msg);
} catch (err) {
alert('Oops, unable to copy');
}
document.body.removeChild(textArea);
}
function updateChart(initialWeight, currentWeight, targetWeight, timePeriod, unitSuffix) {
var ctx = document.getElementById('weightLossChart').getContext('2d');
// Destroy previous chart instance if it exists
if (weightLossChartInstance) {
weightLossChartInstance.destroy();
}
var chartData = {
labels: ['Start', 'Current', 'Target'],
datasets: [
{
label: 'Weight (' + unitSuffix + ')',
data: [initialWeight, currentWeight, targetWeight],
backgroundColor: 'rgba(0, 74, 153, 0.5)', // Primary color
borderColor: 'rgba(0, 74, 153, 1)',
borderWidth: 2,
fill: false,
pointRadius: 6,
pointHoverRadius: 8
},
{
label: 'Trend Line (Implied)',
// For trend, we need to simulate points. Let's assume linear progression.
// Start point: (0 weeks, initialWeight)
// End point: (timePeriod weeks, currentWeight)
// To project to target, we need to calculate time to target.
// For simplicity in this example, we'll just show a line between Start and Current.
// A more complex chart could project further.
data: [initialWeight, currentWeight], // Simplified for now
backgroundColor: 'rgba(40, 167, 69, 0.5)', // Success color
borderColor: 'rgba(40, 167, 69, 1)',
borderWidth: 2,
fill: false,
pointRadius: 0, // No specific points for trend line
pointHoverRadius: 0
}
]
};
// Add a point for Estimated Time to Target if available and valid
if (document.getElementById('estimatedTimeToTarget').textContent !== 'N/A' && document.getElementById('estimatedTimeToTarget').textContent !== 'Target Achieved') {
var estimatedWeeks = parseFloat(document.getElementById('estimatedTimeToTarget').textContent);
if (!isNaN(estimatedWeeks)) {
chartData.labels.push('Estimated Target');
chartData.datasets[0].data.push(targetWeight); // Target weight value
chartData.datasets[1].data.push(targetWeight); // Trend line needs to reach target
// Adjust timePeriod for chart if estimated time is longer
var extendedTimePeriod = Math.max(timePeriod, estimatedWeeks);
chartData.labels[0] = 'Start (0 wks)'; // Update label if needed
chartData.labels[1] = 'Current (' + timePeriod + ' wks)';
chartData.labels[2] = 'Target';
chartData.labels[3] = 'Est. Target Reached';
// Add a placeholder for the time axis if needed, though this chart is simplified
}
} else if (document.getElementById('estimatedTimeToTarget').textContent === 'Target Achieved') {
chartData.labels.push('Target Achieved');
chartData.datasets[0].data.push(targetWeight);
chartData.datasets[1].data.push(targetWeight);
chartData.labels[0] = 'Start (0 wks)';
chartData.labels[1] = 'Current (' + timePeriod + ' wks)';
}
weightLossChartInstance = new Chart(ctx, {
type: 'line',
data: chartData,
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
y: {
beginAtZero: false,
title: {
display: true,
text: 'Weight (' + unitSuffix + ')'
}
},
x: {
title: {
display: true,
text: 'Time (Weeks)'
}
}
},
plugins: {
title: {
display: true,
text: 'Weight Progression and Target Projection'
},
tooltip: {
callbacks: {
label: function(context) {
var label = context.dataset.label || '';
if (label) {
label += ': ';
}
if (context.parsed.y !== null) {
label += context.parsed.y.toFixed(2) + ' ' + unitSuffix;
}
return label;
}
}
}
}
}
});
}
// Initial calculation and unit display update on page load
window.onload = function() {
updateUnitDisplay();
calculateWeightLoss(); // Perform initial calculation
};