Weight Loss Calculator in Pounds

Weight Loss Calculator in Pounds | Estimate Your Weight Loss Journey body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: #f8f9fa; color: #333; line-height: 1.6; margin: 0; padding: 0; } .container { max-width: 960px; margin: 20px auto; padding: 20px; background-color: #fff; border-radius: 8px; box-shadow: 0 2px 10px rgba(0, 74, 153, 0.1); } h1, h2, h3 { color: #004a99; } h1 { text-align: center; margin-bottom: 30px; font-size: 2.2em; } .calculator-section { background-color: #ffffff; padding: 30px; border-radius: 8px; box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05); margin-bottom: 30px; } .input-group { margin-bottom: 20px; text-align: left; } .input-group label { display: block; margin-bottom: 8px; font-weight: bold; color: #004a99; } .input-group input[type="number"], .input-group select { width: calc(100% – 20px); padding: 12px 10px; border: 1px solid #ccc; border-radius: 5px; font-size: 1em; box-sizing: border-box; } .input-group input[type="number"]:focus, .input-group select:focus { border-color: #004a99; outline: none; box-shadow: 0 0 0 3px rgba(0, 74, 153, 0.2); } .input-group .helper-text { font-size: 0.85em; color: #666; margin-top: 5px; display: block; } .error-message { color: #dc3545; font-size: 0.9em; margin-top: 5px; display: block; min-height: 1.2em; /* Prevent layout shift */ } .button-group { text-align: center; margin-top: 30px; } .button-group button { background-color: #004a99; color: white; border: none; padding: 12px 25px; border-radius: 5px; cursor: pointer; font-size: 1em; margin: 5px; transition: background-color 0.3s ease; } .button-group button:hover { background-color: #003b7d; } .button-group button.reset { background-color: #6c757d; } .button-group button.reset:hover { background-color: #5a6268; } .results-section { margin-top: 30px; padding: 25px; background-color: #e9ecef; border-radius: 8px; border: 1px solid #dee2e6; } .results-section h2 { margin-top: 0; color: #004a99; text-align: center; } .primary-result { font-size: 2.5em; font-weight: bold; color: #28a745; text-align: center; margin: 20px 0; background-color: #d4edda; padding: 15px; border-radius: 5px; } .intermediate-results { display: flex; justify-content: space-around; flex-wrap: wrap; margin-top: 25px; } .intermediate-results div { text-align: center; margin: 10px; padding: 10px 15px; background-color: #fff; border-radius: 5px; box-shadow: 0 1px 3px rgba(0,0,0,0.1); flex: 1; min-width: 150px; } .intermediate-results div strong { display: block; font-size: 1.4em; color: #004a99; } .intermediate-results div span { font-size: 0.9em; color: #555; } .formula-explanation { font-size: 0.95em; color: #555; margin-top: 20px; padding: 15px; background-color: #f1f3f5; border-left: 4px solid #004a99; border-radius: 3px; } table { width: 100%; border-collapse: collapse; margin-top: 30px; } th, td { padding: 12px; text-align: left; border-bottom: 1px solid #ddd; } thead th { background-color: #004a99; color: white; } tbody tr:nth-child(even) { background-color: #f2f2f2; } caption { font-size: 1.1em; font-weight: bold; margin-bottom: 15px; color: #004a99; caption-side: top; } canvas { display: block; margin: 30px auto; max-width: 100%; background-color: #fff; border-radius: 5px; box-shadow: 0 2px 8px rgba(0,0,0,0.05); } .article-content { margin-top: 40px; padding: 30px; background-color: #fff; border-radius: 8px; box-shadow: 0 2px 8px rgba(0,0,0,0.05); } .article-content h2 { margin-top: 30px; margin-bottom: 15px; border-bottom: 2px solid #eee; padding-bottom: 5px; } .article-content h3 { margin-top: 20px; margin-bottom: 10px; } .article-content p { margin-bottom: 15px; } .article-content ul, .article-content ol { margin-left: 20px; margin-bottom: 15px; } .article-content li { margin-bottom: 8px; } .faq-item { margin-bottom: 15px; border-left: 3px solid #004a99; padding-left: 10px; } .faq-item strong { display: block; color: #004a99; margin-bottom: 5px; } .internal-links { margin-top: 30px; padding: 20px; background-color: #e9ecef; border-radius: 8px; border: 1px solid #dee2e6; } .internal-links h3 { margin-top: 0; color: #004a99; text-align: center; margin-bottom: 20px; } .internal-links ul { list-style: none; padding: 0; } .internal-links li { margin-bottom: 10px; } .internal-links a { color: #004a99; text-decoration: none; font-weight: bold; } .internal-links a:hover { text-decoration: underline; } .internal-links p { font-size: 0.9em; color: #555; margin-top: 5px; }

Weight Loss Calculator in Pounds

Estimate your weight loss timeline and progress based on calorie intake and expenditure.

Weight Loss Calculator

Enter your current weight in pounds.
Enter your desired weight in pounds.
The number of calories you aim to consume less than you burn each week. (e.g., 500, 1000, 1500)

Your Weight Loss Projection

— lbs to lose
Total Weight to Lose (lbs)
Estimated Weeks to Reach Target
Average Daily Calorie Deficit (kcal)
How it works: This calculator estimates your weight loss based on the principle that approximately 3,500 calories equal one pound of body fat. By inputting your desired weekly calorie deficit, we calculate the total number of weeks required to achieve your target weight. The daily calorie deficit is derived from your weekly deficit.

Estimated weight loss over time.

Weight Loss Progress Breakdown
Week Estimated Weight Loss This Week (lbs) Total Weight Lost (lbs) Estimated Weight at End of Week (lbs)

What is a Weight Loss Calculator in Pounds?

{primary_keyword} is a valuable online tool designed to help individuals estimate the time and effort required to reach a specific weight loss goal. It takes into account your current weight, your target weight, and a projected weekly calorie deficit to provide a timeline for your weight loss journey. Understanding these metrics can provide motivation and a clear roadmap for achieving your health objectives.

This calculator is particularly useful for anyone looking to lose weight in a structured and measurable way. Whether you're aiming for a modest few pounds or a more significant transformation, a {primary_keyword} can help set realistic expectations. It's a fantastic resource for individuals who prefer data-driven approaches to health and fitness.

A common misconception about weight loss calculators is that they offer a guaranteed outcome. It's important to remember that these are *estimates*. Individual metabolic rates, exercise consistency, hormonal fluctuations, and dietary adherence can all influence the actual pace of weight loss. This tool provides a strong starting point, not an infallible prediction.

Weight Loss Calculator in Pounds Formula and Mathematical Explanation

The core of the {primary_keyword} relies on a well-established principle in weight management: the calorie deficit. Here's a breakdown of the formula and its components:

1. Total Weight to Lose: This is the difference between your current weight and your target weight.

Total Weight to Lose (lbs) = Current Weight (lbs) - Target Weight (lbs)

2. Calories per Pound: It is widely accepted that one pound of body fat is equivalent to approximately 3,500 calories. This is a foundational number for most weight loss calculations.

3. Estimated Weeks to Reach Target: To find the number of weeks, we divide the total weight to lose by the amount of weight you aim to lose each week. This weekly weight loss is derived from your calorie deficit.

Weekly Weight Loss (lbs) = Weekly Calorie Deficit (kcal) / 3500 (kcal/lb)

Estimated Weeks = Total Weight to Lose (lbs) / Weekly Weight Loss (lbs)

4. Average Daily Calorie Deficit: This is simply your weekly calorie deficit divided by the number of days in a week.

Average Daily Calorie Deficit (kcal) = Weekly Calorie Deficit (kcal) / 7 (days/week)

Variables Table for Weight Loss Calculator

Weight Loss Calculator Variables
Variable Meaning Unit Typical Range/Notes
Current Weight Your starting body weight. Pounds (lbs) Positive number, e.g., 100 – 500+
Target Weight Your desired end body weight. Pounds (lbs) Positive number, less than current weight, e.g., 100 – 490+
Weekly Calorie Deficit The net reduction in calories consumed vs. burned per week. Kilocalories (kcal) / week Positive number, common ranges are 500 – 1500 kcal/week. A deficit of 3500-7000 kcal/week typically leads to 1-2 lbs loss per week.
Total Weight to Lose The total amount of weight that needs to be lost. Pounds (lbs) Calculated value, must be positive.
Estimated Weeks The calculated duration to reach the target weight. Weeks Calculated value, typically positive.
Average Daily Calorie Deficit The average calorie reduction per day. Kilocalories (kcal) / day Calculated value, must be positive.

Practical Examples (Real-World Use Cases)

Let's illustrate the use of the {primary_keyword} with two practical scenarios:

Example 1: Moderate Weight Loss Goal

Scenario: Sarah wants to lose 20 pounds. She has determined that through a combination of dietary changes and increased activity, she can safely maintain a weekly calorie deficit of 750 kcal.

Inputs:

  • Current Weight: 160 lbs
  • Target Weight: 140 lbs
  • Weekly Calorie Deficit: 750 kcal

Calculations:

  • Total Weight to Lose: 160 lbs – 140 lbs = 20 lbs
  • Weekly Weight Loss: 750 kcal / 3500 kcal/lb ≈ 0.214 lbs/week
  • Estimated Weeks: 20 lbs / 0.214 lbs/week ≈ 93.5 weeks
  • Average Daily Calorie Deficit: 750 kcal / 7 days ≈ 107 kcal/day

Interpretation: Sarah's goal of losing 20 pounds with a 750 kcal weekly deficit will take approximately 93.5 weeks, or about 1 year and 9 months. This highlights that very small deficits lead to very slow weight loss. She might consider increasing her deficit if her doctor advises it's safe and sustainable for her.

Example 2: Significant Weight Loss Goal

Scenario: John needs to lose 50 pounds for health reasons. He is committed to a stricter regimen and aims for a weekly calorie deficit of 1250 kcal.

Inputs:

  • Current Weight: 220 lbs
  • Target Weight: 170 lbs
  • Weekly Calorie Deficit: 1250 kcal

Calculations:

  • Total Weight to Lose: 220 lbs – 170 lbs = 50 lbs
  • Weekly Weight Loss: 1250 kcal / 3500 kcal/lb ≈ 0.357 lbs/week
  • Estimated Weeks: 50 lbs / 0.357 lbs/week ≈ 140 weeks
  • Average Daily Calorie Deficit: 1250 kcal / 7 days ≈ 179 kcal/day

Interpretation: John's 50-pound weight loss goal with a 1250 kcal weekly deficit would realistically take about 140 weeks, or nearly 3 years. This demonstrates that even with a significant deficit, losing large amounts of weight takes considerable time. It's crucial to maintain consistency and focus on sustainable lifestyle changes. This calculation also prompts a review: is the weekly deficit realistic and sustainable? If John can manage a deficit of 1750 kcal (approx. 250 kcal/day), he might lose closer to 0.5 lbs/week, cutting down the timeline significantly.

How to Use This Weight Loss Calculator in Pounds

Utilizing the {primary_keyword} is straightforward. Follow these steps to get your personalized weight loss projection:

  1. Enter Current Weight: Input your current body weight in pounds into the "Current Weight" field.
  2. Enter Target Weight: Enter the weight in pounds you aim to achieve in the "Target Weight" field. Ensure this is less than your current weight.
  3. Set Weekly Calorie Deficit: Input the number of calories you intend to reduce from your diet and daily activity each week into the "Weekly Calorie Deficit" field. A common, sustainable deficit for losing 1-2 pounds per week is between 500 to 1000 kcal. A deficit of 3500 kcal corresponds to roughly 1 pound of fat loss.
  4. Click Calculate: Press the "Calculate Weight Loss" button.

How to Read Results:

  • Primary Result (lbs to lose): This large, highlighted number shows your total weight loss goal in pounds.
  • Intermediate Values: You'll see the total weight to lose, the estimated number of weeks required to reach your target, and your average daily calorie deficit.
  • Progress Table: A detailed breakdown shows your estimated weight loss week by week.
  • Chart: A visual representation of your projected weight loss over time.

Decision-Making Guidance:

  • Realistic Timelines: The results will reveal whether your chosen deficit is aggressive or conservative. If the timeline seems too long, you might need to adjust your deficit (if safely possible) or re-evaluate your target weight.
  • Sustainability: A very large calorie deficit might seem appealing for quick results, but it's often unsustainable and can lead to nutrient deficiencies or muscle loss. The calculator helps you understand the trade-off between speed and sustainability.
  • Motivation: Seeing the projected timeline can be a powerful motivator. Break down the larger goal into smaller, manageable weekly targets.

Don't forget to use the calculator to experiment with different scenarios!

Key Factors That Affect Weight Loss Calculator Results

While the {primary_keyword} provides a solid estimate, numerous factors can influence your actual weight loss progress. Understanding these nuances is crucial for setting realistic expectations and maintaining motivation:

  1. Metabolic Rate (Basal Metabolic Rate – BMR): Your BMR is the number of calories your body burns at rest. Factors like age, sex, muscle mass, and genetics significantly impact BMR. A higher BMR means your body burns more calories naturally, potentially accelerating weight loss.
  2. Thermic Effect of Food (TEF): Digesting, absorbing, and metabolizing food also burns calories. Protein, for instance, has a higher TEF than fats or carbohydrates, meaning your body works harder to process it. This can subtly increase your daily calorie expenditure beyond your programmed deficit.
  3. Activity Level & Exercise: The calculator's deficit is an estimate. The actual calories burned through daily activities (NEAT – Non-Exercise Activity Thermogenesis) and planned exercise sessions can greatly vary. Consistently engaging in physical activity will increase your total daily energy expenditure (TDEE), effectively increasing your deficit and speeding up weight loss.
  4. Muscle Mass vs. Fat Mass: Weight loss isn't just about shedding pounds; it's about losing fat while preserving or building muscle. Muscle is metabolically active and burns more calories than fat. If your deficit is too severe or lacks sufficient protein and resistance training, you might lose muscle, slowing your metabolism and potentially impacting your long-term weight loss success.
  5. Hormonal Fluctuations: Hormones play a significant role in appetite, metabolism, and fat storage. For women, menstrual cycles can cause temporary water retention and changes in appetite. Conditions like thyroid issues or PCOS can also affect weight loss.
  6. Sleep Quality and Stress Levels: Poor sleep and high stress levels can disrupt hormones like cortisol and ghrelin, which can increase appetite, promote fat storage (especially around the abdomen), and decrease motivation for healthy eating and exercise.
  7. Hydration: Adequate water intake is essential for metabolism and can help you feel fuller, potentially reducing overall calorie consumption. Dehydration can temporarily slow down metabolic processes.
  8. Dietary Adherence and Accuracy: The accuracy of your calorie deficit depends on meticulously tracking your food intake and activity. Underestimating portion sizes or "forgetting" snacks can significantly reduce your actual deficit, leading to slower progress than predicted by the {primary_keyword}.

Frequently Asked Questions (FAQ)

Q1: Is 3500 calories really equal to 1 pound of fat?

A1: The 3500-calorie rule is a widely used approximation. While it's a convenient benchmark, the precise metabolic conversion can vary slightly between individuals and even based on the type of tissue being lost (fat vs. lean mass).

Q2: Can I achieve a faster weight loss by creating a larger calorie deficit?

A2: Yes, a larger deficit will mathematically lead to faster weight loss. However, very large deficits (e.g., over 1000-1500 kcal per day) can be difficult to sustain, lead to nutrient deficiencies, muscle loss, fatigue, and may not be healthy or recommended without medical supervision. A gradual approach is generally more sustainable.

Q3: What is a safe and sustainable weekly calorie deficit for weight loss?

A3: For most people, a deficit of 500 to 1000 kcal per day (resulting in roughly 1-2 pounds of weight loss per week) is considered safe and sustainable. This is achieved by combining dietary changes and increased physical activity.

Q4: My results show a very long timeline. What can I do?

A4: If the projected timeline is longer than you expected, consider if you can safely and sustainably increase your weekly calorie deficit. This might involve making small, consistent adjustments to your diet or gradually increasing your exercise routine. Alternatively, re-evaluate your target weight for a more achievable short-to-medium term goal.

Q5: Does the calculator account for exercise?

A5: The calculator estimates based on a *net* weekly calorie deficit. This deficit is the result of your calorie intake minus your total daily energy expenditure (which includes your BMR, TEF, and activity/exercise). You input your *intended* weekly deficit, and it's up to you to ensure your diet and exercise habits create that deficit.

Q6: What happens if my target weight is higher than my current weight?

A6: The calculator is designed for weight loss, meaning the target weight should be lower than the current weight. If you enter a target weight higher than your current weight, the "Total Weight to Lose" will be negative, and the results might not be meaningful. Please ensure your target weight is less than your current weight.

Q7: How often should I recalculate my weight loss?

A7: As you lose weight, your body composition changes, and your metabolic rate may also adjust. It's a good idea to re-evaluate your progress and potentially recalculate using the {primary_keyword} every 4-8 weeks, or whenever you reach a new plateau or significantly change your diet/exercise plan.

Q8: Can this calculator predict weight loss for bodybuilding or muscle gain?

A8: No, this specific calculator is designed for estimating fat loss based on a calorie deficit. It does not account for bulking phases or significant muscle gain, which involve different caloric strategies (often a surplus).

© 2023 Your Website Name. All rights reserved. This calculator and information are for educational purposes only and do not constitute medical advice.

var currentWeightInput = document.getElementById('currentWeight'); var targetWeightInput = document.getElementById('targetWeight'); var weeklyCalorieDeficitInput = document.getElementById('weeklyCalorieDeficit'); var currentWeightError = document.getElementById('currentWeightError'); var targetWeightError = document.getElementById('targetWeightError'); var weeklyCalorieDeficitError = document.getElementById('weeklyCalorieDeficitError'); var totalWeightToLoseDisplay = document.getElementById('totalWeightToLose'); var totalWeeksDisplay = document.getElementById('totalWeeks'); var dailyCalorieDeficitDisplay = document.getElementById('dailyCalorieDeficit'); var resultDisplay = document.getElementById('result'); var progressTableBody = document.getElementById('progressTableBody'); var weightLossChartCanvas = document.getElementById('weightLossChart'); var weightLossChartContext = weightLossChartCanvas.getContext('2d'); var weightLossChartInstance = null; var CALORIES_PER_POUND = 3500; function validateInput(inputElement, errorElement, minValue, maxValue, inputName) { var value = parseFloat(inputElement.value); var errorMessage = ""; if (isNaN(value) || inputElement.value.trim() === "") { errorMessage = inputName + " is required."; } else if (value = parseFloat(currentWeightInput.value)) { errorMessage = inputName + " must be less than current weight."; } else if (inputName === "Current Weight" && value <= parseFloat(targetWeightInput.value)) { errorMessage = inputName + " must be greater than target weight."; } else if (inputName === "Weekly Calorie Deficit") { if (value 2000) errorMessage = inputName + " over 2000 kcal may be too aggressive without medical advice."; } errorElement.textContent = errorMessage; return errorMessage === ""; } function calculateWeightLoss() { var isValid = true; isValid &= validateInput(currentWeightInput, currentWeightError, 0, Infinity, "Current Weight"); isValid &= validateInput(targetWeightInput, targetWeightError, 0, Infinity, "Target Weight"); isValid &= validateInput(weeklyCalorieDeficitInput, weeklyCalorieDeficitError, 0, Infinity, "Weekly Calorie Deficit"); if (!isValid) { resetResults(); return; } var currentWeight = parseFloat(currentWeightInput.value); var targetWeight = parseFloat(targetWeightInput.value); var weeklyCalorieDeficit = parseFloat(weeklyCalorieDeficitInput.value); var totalWeightToLose = currentWeight – targetWeight; var weeklyWeightLossRate = weeklyCalorieDeficit / CALORIES_PER_POUND; var estimatedWeeks = totalWeightToLose / weeklyWeightLossRate; var dailyCalorieDeficit = weeklyCalorieDeficit / 7; resultDisplay.textContent = totalWeightToLose.toFixed(1) + " lbs to lose"; totalWeightToLoseDisplay.textContent = totalWeightToLose.toFixed(1); totalWeeksDisplay.textContent = estimatedWeeks.toFixed(1); dailyCalorieDeficitDisplay.textContent = dailyCalorieDeficit.toFixed(0); updateProgressTable(currentWeight, weeklyWeightLossRate, estimatedWeeks); updateChart(currentWeight, totalWeightToLose, estimatedWeeks); } function resetResults() { resultDisplay.textContent = "– lbs to lose"; totalWeightToLoseDisplay.textContent = "–"; totalWeeksDisplay.textContent = "–"; dailyCalorieDeficitDisplay.textContent = "–"; progressTableBody.innerHTML = ""; if (weightLossChartInstance) { weightLossChartInstance.destroy(); weightLossChartInstance = null; } weightLossChartCanvas.style.display = 'none'; // Hide canvas until new calculation } function resetCalculator() { currentWeightInput.value = "200"; targetWeightInput.value = "170"; weeklyCalorieDeficitInput.value = "1000"; currentWeightError.textContent = ""; targetWeightError.textContent = ""; weeklyCalorieDeficitError.textContent = ""; resetResults(); calculateWeightLoss(); // Recalculate with default values } function copyResults() { var currentWeight = parseFloat(currentWeightInput.value); var targetWeight = parseFloat(targetWeightInput.value); var weeklyCalorieDeficit = parseFloat(weeklyCalorieDeficitInput.value); var totalWeightToLose = currentWeight – targetWeight; var weeklyWeightLossRate = weeklyCalorieDeficit / CALORIES_PER_POUND; var estimatedWeeks = totalWeightToLose / weeklyWeightLossRate; var dailyCalorieDeficit = weeklyCalorieDeficit / 7; var resultText = "Weight Loss Projection:\n"; resultText += "———————–\n"; resultText += "Current Weight: " + currentWeight.toFixed(1) + " lbs\n"; resultText += "Target Weight: " + targetWeight.toFixed(1) + " lbs\n"; resultText += "Weekly Calorie Deficit: " + weeklyCalorieDeficit.toFixed(0) + " kcal\n"; resultText += "———————–\n"; resultText += "Total Weight to Lose: " + totalWeightToLose.toFixed(1) + " lbs\n"; resultText += "Estimated Weeks to Target: " + estimatedWeeks.toFixed(1) + " weeks\n"; resultText += "Average Daily Calorie Deficit: " + dailyCalorieDeficit.toFixed(0) + " kcal\n"; resultText += "\nBased on approximately 3500 kcal per pound."; var textArea = document.createElement("textarea"); textArea.value = resultText; document.body.appendChild(textArea); textArea.select(); document.execCommand("copy"); textArea.remove(); alert("Results copied to clipboard!"); } function updateProgressTable(startWeight, weeklyLossRate, totalWeeks) { progressTableBody.innerHTML = ""; // Clear previous table rows var currentRowWeight = startWeight; var totalLost = 0; // Limit table rows to a reasonable number to prevent performance issues var maxTableRows = 52; // Show up to one year of data var weeksToDisplay = Math.min(Math.ceil(totalWeeks), maxTableRows); for (var i = 1; i <= weeksToDisplay; i++) { var weightLossThisWeek = weeklyLossRate; var weightAtEndOfWeek = startWeight – (i * weeklyLossRate); // Ensure weight doesn't go below target if it's reached within the displayed weeks if (weightAtEndOfWeek < targetWeightInput.value && i <= totalWeeks) { weightLossThisWeek = currentRowWeight – parseFloat(targetWeightInput.value); weightAtEndOfWeek = parseFloat(targetWeightInput.value); totalLost = startWeight – weightAtEndOfWeek; } else { totalLost = i * weeklyLossRate; } if (weightAtEndOfWeek < 0) weightAtEndOfWeek = 0; // Prevent negative weight var row = progressTableBody.insertRow(); var cellWeek = row.insertCell(0); var cellLossThisWeek = row.insertCell(1); var cellTotalLost = row.insertCell(2); var cellEndWeight = row.insertCell(3); cellWeek.textContent = i; cellLossThisWeek.textContent = weightLossThisWeek.toFixed(2); cellTotalLost.textContent = totalLost.toFixed(2); cellEndWeight.textContent = weightAtEndOfWeek.toFixed(1); if (weightAtEndOfWeek === parseFloat(targetWeightInput.value)) { // Highlight the row where target is met row.style.backgroundColor = "#d4edda"; row.style.fontWeight = "bold"; } } } function updateChart(startWeight, totalWeightToLose, totalWeeks) { if (weightLossChartInstance) { weightLossChartInstance.destroy(); } weightLossChartCanvas.style.display = 'block'; // Make canvas visible weightLossChartInstance = new Chart(weightLossChartContext, { type: 'line', data: { labels: generateChartLabels(totalWeeks), datasets: [ { label: 'Projected Weight (lbs)', data: generateWeightData(startWeight, totalWeightToLose, totalWeeks), borderColor: '#004a99', backgroundColor: 'rgba(0, 74, 153, 0.2)', fill: true, tension: 0.1 }, { label: 'Target Weight (lbs)', data: Array(generateChartLabels(totalWeeks).length).fill(parseFloat(targetWeightInput.value)), borderColor: '#28a745', borderDash: [5, 5], backgroundColor: 'rgba(40, 167, 69, 0.2)', fill: false, tension: 0 } ] }, options: { responsive: true, maintainAspectRatio: false, scales: { x: { title: { display: true, text: 'Weeks' } }, y: { title: { display: true, text: 'Weight (lbs)' }, beginAtZero: false // Start y-axis slightly below the lowest expected weight } }, plugins: { tooltip: { mode: 'index', intersect: false, }, legend: { position: 'top', } }, hover: { mode: 'nearest', intersect: true } } }); } function generateChartLabels(totalWeeks) { var labels = []; var numLabels = Math.min(Math.ceil(totalWeeks) + 1, 50); // Limit labels for clarity, add 1 for start var interval = totalWeeks / (numLabels – 1); for (var i = 0; i < numLabels; i++) { labels.push((i * interval).toFixed(1)); } return labels; } function generateWeightData(startWeight, totalWeightToLose, totalWeeks) { var data = []; var numLabels = Math.min(Math.ceil(totalWeeks) + 1, 50); var interval = totalWeeks / (numLabels – 1); var weeklyLossRate = (totalWeightToLose / totalWeeks); // Recalculate for chart accuracy for (var i = 0; i < numLabels; i++) { var week = i * interval; var projectedWeight = startWeight – (week * weeklyLossRate); if (projectedWeight < parseFloat(targetWeightInput.value)) { projectedWeight = parseFloat(targetWeightInput.value); } data.push(projectedWeight.toFixed(1)); } return data; } function handleInitialLoad() { // Attempt to load Chart.js if it's not already loaded if (typeof Chart === 'undefined') { var script = document.createElement('script'); script.src = 'https://cdn.jsdelivr.net/npm/chart.js@3.9.1/dist/chart.min.js'; script.onload = function() { calculateWeightLoss(); // Proceed with calculation after Chart.js is loaded }; script.onerror = function() { alert('Failed to load charting library. Chart functionality will be unavailable.'); calculateWeightLoss(); // Still calculate other parts }; document.head.appendChild(script); } else { calculateWeightLoss(); // Calculate immediately if Chart.js is already available } } // Initial calculation on page load window.onload = handleInitialLoad;

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