Weight Loss Progression Calculator

Weight Loss Progression Calculator – Track Your Journey :root { –primary-color: #004a99; –success-color: #28a745; –background-color: #f8f9fa; –text-color: #333; –border-color: #ccc; –input-bg: #fff; –shadow-color: rgba(0, 0, 0, 0.1); } body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: var(–background-color); color: var(–text-color); margin: 0; padding: 0; display: flex; justify-content: center; padding: 20px; } .container { max-width: 1000px; width: 100%; background-color: #fff; padding: 30px; border-radius: 8px; box-shadow: 0 4px 12px var(–shadow-color); margin: 20px auto; } h1, h2, h3 { color: var(–primary-color); text-align: center; } h1 { margin-bottom: 10px; font-size: 2.5em; } .subtitle { text-align: center; font-size: 1.1em; color: #555; margin-bottom: 30px; } .calculator-section { background-color: var(–input-bg); border: 1px solid var(–border-color); border-radius: 8px; padding: 25px; margin-bottom: 30px; } .loan-calc-container { display: flex; 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Weight Loss Progression Calculator

Track your weight loss journey and see your progress over time.

Calculate Your Weight Loss Progression

Enter your current body weight.
Enter your target body weight.
Date when you weighed your current weight.
Desired date to reach your goal weight.
Average kilograms you aim to lose per week.
Kilograms (kg) Pounds (lbs)
Select your preferred unit of weight measurement.

Your Weight Loss Progress

Total Weight to Lose:
Estimated Weeks to Goal (based on rate):
Estimated Weeks to Goal (based on dates):
Average Daily Loss Rate (kg/day):
Calculations are based on the difference between current and goal weight, the difference between the start and target dates, and your desired weekly loss rate.

Weight Loss Over Time

Projected weight loss based on your inputs.

Weight Loss Milestones

Week Date Projected Weight (kg)
Key weight loss milestones to keep you motivated.

What is a Weight Loss Progression Calculator?

A Weight Loss Progression Calculator is a digital tool designed to help individuals track, analyze, and project their weight loss journey. It takes key inputs like your current weight, goal weight, the timeframe you wish to achieve it within, and your desired rate of loss to provide insights into your progress. This calculator is invaluable for anyone looking to understand how much weight they need to lose, how quickly they can realistically achieve their goals, and what daily or weekly loss rate is required.

Who should use it? Anyone embarking on a weight loss journey, from beginners to those who have been trying for some time, can benefit. It's particularly useful for setting realistic expectations, staying motivated, and making informed adjustments to your diet and exercise plan. Whether you're aiming for a specific number on the scale or a general improvement in health, this tool can guide you.

Common misconceptions: A frequent misconception is that weight loss is purely linear or that one size fits all. In reality, weight loss can fluctuate. This calculator provides an *average* progression, and it's important to remember that individual results may vary due to metabolism, adherence to diet and exercise, hormonal changes, and other biological factors. Another misconception is that the calculator predicts exact outcomes; it provides estimates based on the data provided.

Weight Loss Progression Calculator Formula and Mathematical Explanation

The core of the weight loss progression calculator involves several interconnected calculations to provide a comprehensive view of your weight loss journey. We aim to estimate the time required to reach your goal and your average rate of loss.

Key Calculations:

  1. Total Weight to Lose: This is the fundamental difference between your starting point and your target.
    Total Weight to Lose = Current Weight - Goal Weight
  2. Weeks to Goal (based on desired rate): This calculation determines how many weeks it will take to reach your goal if you consistently lose weight at your specified weekly rate.
    Weeks to Goal (Rate) = Total Weight to Lose / Desired Weekly Loss Rate
  3. Weeks to Goal (based on dates): This calculates the number of weeks between your start date and your target date, providing a benchmark for your goal timeframe.
    Weeks to Goal (Dates) = (Target Date - Start Date) / 7 (days in a week)
  4. Average Daily Loss Rate: This computes the average amount of weight you need to lose each day to reach your goal by your target date.
    Average Daily Loss Rate = Total Weight to Lose / (Weeks to Goal (Dates) * 7)
  5. Average Weekly Loss Rate (from dates): Derived from the daily rate.
    Average Weekly Loss Rate (from dates) = Average Daily Loss Rate * 7
  6. Projected Weight at Milestones: For weekly projections, we calculate the weight at the end of each week.
    Projected Weight (Week N) = Current Weight - (Desired Weekly Loss Rate * N)

Variable Explanations:

Let's break down the variables used in our weight loss progression calculator:

Variable Meaning Unit Typical Range
Current Weight Your starting body weight at the beginning of the tracking period. Kilograms (kg) or Pounds (lbs) 1 – 1000 (depending on unit)
Goal Weight The target body weight you aim to achieve. Kilograms (kg) or Pounds (lbs) 1 – 1000 (depending on unit)
Start Date The date on which your current weight was recorded. Date YYYY-MM-DD
Target Date The desired date by which you aim to reach your goal weight. Date YYYY-MM-DD
Desired Weekly Loss Rate The average amount of weight you aim to lose per week. Kilograms (kg) or Pounds (lbs) per week 0.1 – 2.0 (Recommended: 0.5 – 1.0 kg/week for sustainable loss)
Total Weight to Lose The total difference between current and goal weight. Kilograms (kg) or Pounds (lbs) 0 – (Current Weight – Goal Weight)
Weeks to Goal (Rate) Estimated weeks to reach goal based on consistent weekly loss. Weeks Positive number, can be very large if rate is low.
Weeks to Goal (Dates) Total number of weeks between start and target dates. Weeks Positive number, depends on date difference.
Average Daily Loss Rate Average daily weight loss required to meet the date goal. Kilograms (kg) or Pounds (lbs) per day 0 – ~0.2 (for a 1kg/week goal over 10 weeks)

Practical Examples (Real-World Use Cases)

Let's illustrate how the weight loss progression calculator can be used with practical scenarios:

Example 1: Sustainable Weight Loss Goal

  • Current Weight: 80 kg
  • Goal Weight: 70 kg
  • Start Date: 2023-10-26
  • Target Date: 2024-04-26 (6 months)
  • Desired Weekly Loss: 0.75 kg/week
  • Weight Unit: kg

Calculator Output Interpretation:

  • Total Weight to Lose: 10 kg
  • Estimated Weeks to Goal (based on rate): 10 kg / 0.75 kg/week = ~13.3 weeks
  • Estimated Weeks to Goal (based on dates): Approx. 26 weeks
  • Average Daily Loss Rate: 10 kg / (26 weeks * 7 days/week) = ~0.055 kg/day

Financial Interpretation: In this scenario, the user aims for a sustainable loss rate. The calculation shows that their desired rate (0.75 kg/week) would allow them to reach their goal much faster than their target date. This suggests they might be able to achieve their goal in about 13-14 weeks. They can either adjust their target date to be sooner or reduce their weekly loss rate to make the journey less demanding and more sustainable long-term. For instance, if they aimed for 0.5 kg/week, it would take 20 weeks, aligning better with their 6-month goal.

Example 2: Aggressive Weight Loss for an Event

  • Current Weight: 95 lbs
  • Goal Weight: 85 lbs
  • Start Date: 2023-11-15
  • Target Date: 2024-01-15 (2 months)
  • Desired Weekly Loss: 1.5 lbs/week
  • Weight Unit: lbs

Calculator Output Interpretation:

  • Total Weight to Lose: 10 lbs
  • Estimated Weeks to Goal (based on rate): 10 lbs / 1.5 lbs/week = ~6.7 weeks
  • Estimated Weeks to Goal (based on dates): Approx. 9 weeks
  • Average Daily Loss Rate: 10 lbs / (9 weeks * 7 days/week) = ~0.158 lbs/day

Financial Interpretation: This user has a specific event date and aims for a slightly more aggressive weekly loss rate. The calculator indicates that their desired rate of 1.5 lbs/week is more than sufficient to meet their 2-month target, likely achieving it in under 7 weeks. This gives them a buffer. They could potentially slightly increase their weekly loss rate if medically advised and comfortable, or maintain this rate knowing they will comfortably reach their goal before the event. It's crucial to consult with a healthcare professional before pursuing aggressive weight loss to ensure it's safe and healthy.

How to Use This Weight Loss Progression Calculator

Using our weight loss progression calculator is straightforward. Follow these steps to get personalized insights:

  1. Input Current Metrics: Enter your current weight and select the correct unit (kg or lbs). Input the exact date when this weight was recorded.
  2. Set Your Goal: Enter your target goal weight and select the same unit. Input the date by which you ideally want to achieve this goal.
  3. Define Your Pace: Specify your desired average weekly weight loss rate. A sustainable rate is typically between 0.5 kg (1 lb) and 1 kg (2 lbs) per week.
  4. Calculate: Click the "Calculate Progression" button.

How to read results:

  • Primary Result (e.g., Estimated Weeks to Goal): This highlights the most critical timeframe calculation, often comparing your desired rate to your date-based goal.
  • Total Weight to Lose: A clear number showing the deficit needed.
  • Estimated Weeks to Goal (Rate): How long it takes based *only* on your desired weekly loss.
  • Estimated Weeks to Goal (Dates): How long you have until your target date.
  • Average Daily Loss Rate: The consistent daily deficit required to meet your date goal.
  • Chart and Table: Visualize your projected weight loss week by week and see key milestones.

Decision-making guidance:

Compare the "Estimated Weeks to Goal (Rate)" with "Estimated Weeks to Goal (Dates)".

  • If the rate-based estimate is significantly shorter than the date-based estimate, you're on track to achieve your goal early or can afford a slower, more sustainable pace.
  • If the rate-based estimate is longer than the date-based estimate, you need to either increase your desired weekly loss rate (safely!) or adjust your target date.
  • The "Average Daily Loss Rate" provides a concrete target for daily progress.

Use the generated chart and table to visualize your journey and celebrate milestones. Remember, consistency is key for effective weight loss progression.

Key Factors That Affect Weight Loss Progression Results

While our weight loss progression calculator provides estimates, numerous real-world factors can influence your actual journey. Understanding these can help you set more accurate expectations and adjust your strategy:

  1. Metabolic Rate: Your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) are crucial. Factors like age, sex, muscle mass, and genetics significantly impact how many calories you burn at rest and during activity. A lower metabolic rate requires a larger calorie deficit for the same weight loss.
  2. Calorie Intake Accuracy: The calculator assumes a consistent rate of loss, which directly relates to a consistent calorie deficit. In reality, accurately tracking calorie intake is challenging. Portion distortion, hidden calories, and inaccurate food logging can significantly derail progress.
  3. Exercise Consistency and Intensity: While the calculator focuses on weight difference, exercise plays a dual role: burning calories directly and increasing metabolism long-term by building muscle. Inconsistent or low-intensity exercise will yield slower results than planned.
  4. Hormonal Fluctuations: Hormones like cortisol, insulin, thyroid hormones, and sex hormones can profoundly affect appetite, fat storage, and water retention. Stress, sleep quality, and menstrual cycles can cause temporary weight fluctuations that mask underlying fat loss.
  5. Muscle vs. Fat Loss: Weight alone doesn't tell the whole story. A successful weight loss plan aims to lose fat while preserving or even gaining muscle mass. Muscle is denser than fat, so you might see less change on the scale but significant improvements in body composition and health. The calculator primarily tracks scale weight.
  6. Hydration and Sodium Intake: Water weight can fluctuate daily. Dehydration can also slow metabolism. High sodium intake can lead to water retention, masking fat loss on the scale. These can cause short-term "plateaus" or spikes that aren't reflective of true fat loss progress.
  7. Medications and Health Conditions: Certain medications (e.g., steroids, some antidepressants) and underlying health conditions (like hypothyroidism or PCOS) can make weight loss more challenging by affecting metabolism, appetite, or fluid balance.
  8. Age and Sleep Quality: As we age, metabolism can naturally slow down. Poor sleep quality disrupts hormones regulating appetite (ghrelin and leptin) and can increase cortisol levels, both contributing to weight gain or making loss more difficult.

Frequently Asked Questions (FAQ)

Q1: Is a loss of 1-2 kg (2-4 lbs) per week healthy?

For most individuals, a sustainable and healthy rate of weight loss is considered to be around 0.5 kg to 1 kg (1 to 2 lbs) per week. Losing weight faster than this, especially more than 2 lbs per week consistently, might lead to muscle loss, nutrient deficiencies, gallstones, and fatigue. Our calculator allows you to input your desired rate, but it's always best to aim for a pace recommended by health professionals.

Q2: What if my target date is unrealistic based on my desired loss rate?

If the "Estimated Weeks to Goal (Rate)" is longer than "Estimated Weeks to Goal (Dates)", you have a few options: adjust your target date to be later, increase your desired weekly loss rate (ensure it's safe and sustainable, ideally under 1kg/week), or accept that you might not reach your goal by the specific date. Reassessing your goals with realistic expectations is key.

Q3: How often should I update my weight in the calculator?

For tracking progression, it's best to update your weight weekly, ideally around the same day and time, after accounting for normal daily fluctuations. Some people prefer to weigh in daily to see trends, but focus on the weekly average for the most accurate picture of fat loss.

Q4: Does the calculator account for muscle gain?

No, this calculator primarily focuses on the change in scale weight. It doesn't differentiate between fat loss and muscle gain/loss. If you're engaging in strength training, you might gain muscle while losing fat, which could mean the scale doesn't move as quickly as the calculator predicts, even though your body composition is improving. Consider body measurements or body fat percentage for a more complete picture.

Q5: What does "Average Daily Loss Rate" mean if I don't lose weight every single day?

The "Average Daily Loss Rate" is a mathematical target required to meet your goal by the specified date. Weight loss is rarely linear day-to-day. You might gain a little one day and lose more the next. This figure represents the *average* deficit needed. Focus on overall trends and consistency rather than daily fluctuations.

Q6: Can I use this calculator for weight gain goals?

While designed for weight loss, you could technically adapt the logic. If aiming for weight gain, you would input a goal weight higher than your current weight. However, the "Desired Weekly Loss Rate" would need to be reinterpreted as a "Desired Weekly Gain Rate", and the formulas related to loss would need adjustment. For simplicity, this calculator is best used for loss targets.

Q7: What are common reasons for weight loss plateaus?

Plateaus are common and can occur due to various reasons: your body adapting to a lower calorie intake by reducing metabolism, decreased adherence to your diet or exercise plan, muscle gain offsetting fat loss on the scale, hormonal changes, or even increased stress and poor sleep. Re-evaluating your calorie intake, increasing exercise intensity, or consulting a professional can help overcome them.

Q8: How does the unit selection (kg/lbs) affect the results?

The unit selection ensures consistency in your calculations. If you input your current weight in kilograms, your goal weight and desired weekly loss rate should also be in kilograms. The calculator performs the same mathematical operations regardless of the unit chosen; it simply displays the results in the unit you selected for accurate interpretation.

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dateError.style.display = 'block'; dateInput.style.borderColor = '#dc3545'; isValid = false; } else { dateError.style.display = 'none'; dateInput.style.borderColor = '#ccc'; } } return isValid; } function calculateWeightLoss() { var currentWeightInput = getElement("currentWeight"); var goalWeightInput = getElement("goalWeight"); var currentWeightDateInput = getElement("currentWeightDate"); var goalWeightDateInput = getElement("goalWeightDate"); var weeklyRateInput = getElement("weeklyWeightLossRate"); var unitSelect = getElement("weightUnit"); var unit = unitSelect.value; var valid = true; valid = validateInput("currentWeight", 0, null) && valid; valid = validateInput("goalWeight", 0, null) && valid; valid = validateInput("currentWeightDate", null, null) && valid; valid = validateInput("goalWeightDate", null, null) && valid; valid = validateInput("weeklyWeightLossRate", 0.01, 2.0) && valid; // Assuming max reasonable rate of 2kg/lbs per week if (!valid) { getElement("results").style.display = 'none'; return; } var currentWeight = parseFloat(currentWeightInput.value); var goalWeight = parseFloat(goalWeightInput.value); var weeklyRate = parseFloat(weeklyRateInput.value); var currentDate = new Date(currentWeightDateInput.value); var goalDate = new Date(goalWeightDateInput.value); // Ensure goal weight is less than current weight for loss if (goalWeight >= currentWeight) { getElement("goalWeightError").textContent = "Goal weight must be less than current weight for loss."; getElement("goalWeightError").style.display = 'block'; goalWeightInput.style.borderColor = '#dc3545'; valid = false; getElement("results").style.display = 'none'; return; } else { getElement("goalWeightError").style.display = 'none'; goalWeightInput.style.borderColor = '#ccc'; } // Ensure goal date is after current date if (goalDate <= currentDate) { getElement("goalWeightDateError").textContent = "Target date must be after the start date."; getElement("goalWeightDateError").style.display = 'block'; goalWeightDateInput.style.borderColor = '#dc3545'; valid = false; getElement("results").style.display = 'none'; return; } else { getElement("goalWeightDateError").style.display = 'none'; goalWeightDateInput.style.borderColor = '#ccc'; } var totalWeightToLose = currentWeight – goalWeight; var totalWeightToLoseFormatted = totalWeightToLose.toFixed(2) + " " + unit; var timeDiffMilliseconds = goalDate.getTime() – currentDate.getTime(); var timeDiffDays = timeDiffMilliseconds / (1000 * 3600 * 24); var weeksBetweenDates = timeDiffDays / 7; var estimatedWeeksByRate = totalWeightToLose / weeklyRate; var estimatedWeeksByRateFormatted = estimatedWeeksByRate.toFixed(1) + " weeks"; var avgDailyLossRate = totalWeightToLose / timeDiffDays; var avgDailyLossRateFormatted = avgDailyLossRate.toFixed(3) + " " + unit + "/day"; var primaryResultText = ""; var primaryResultLabel = ""; if (estimatedWeeksByRate <= weeksBetweenDates) { primaryResultLabel = "You'll reach your goal in:"; primaryResultText = estimatedWeeksByRate.toFixed(1) + " weeks"; } else { primaryResultLabel = "To reach your goal by the target date, aim for:"; primaryResultText = weeklyRate.toFixed(1) + " " + unit + "/week"; // Alternative primary if dates are the constraint // primaryResultLabel = "Estimated weeks to goal by date:"; // primaryResultText = weeksBetweenDates.toFixed(1) + " weeks"; } getElement("primaryResult").innerHTML = primaryResultText; getElement("totalWeightToLose").textContent = totalWeightToLoseFormatted; getElement("estimatedWeeksByRate").textContent = estimatedWeeksByRateFormatted; getElement("estimatedWeeksByDates").textContent = weeksBetweenDates.toFixed(1) + " weeks"; getElement("avgDailyLossRate").textContent = avgDailyLossRateFormatted; getElement("results").style.display = 'flex'; updateChartAndTable(currentWeight, weeklyRate, weeksBetweenDates, unit, totalWeightToLose, avgDailyLossRate); } function updateChartAndTable(startWeight, weeklyLossRate, totalWeeks, unit, totalWeightToLose, avgDailyLossRate) { var tableBody = getElement("tableBody"); tableBody.innerHTML = ""; // Clear previous data var chartData = []; var maxWeeksForTable = Math.min(Math.ceil(totalWeeks), 20); // Show up to 20 weeks or total duration, whichever is less var currentChartWeight = startWeight; for (var i = 0; i <= maxWeeksForTable; i++) { var currentDate = new Date(); currentDate.setDate(new Date(getElement("currentWeightDate").value).getDate() + (i * 7)); var formattedDate = currentDate.toISOString().split('T')[0]; var projectedWeight = startWeight – (weeklyLossRate * i); if (projectedWeight < parseFloat(getElement("goalWeight").value)) { projectedWeight = parseFloat(getElement("goalWeight").value); // Don't go below goal weight } // Alternative calculation for table using daily average for precise dates var projectedWeightDateBased = parseFloat(getElement("currentWeight").value) – (avgDailyLossRate * (i * 7)); if (projectedWeightDateBased item.week === 0 ? "Start" : `W${item.week}`), datasets: [ { label: 'Projected Weight (' + unit + ')', data: chartData.map(item => item.weight), borderColor: 'var(–primary-color)', backgroundColor: 'rgba(0, 74, 153, 0.1)', fill: true, tension: 0.1 }, { label: 'Goal Weight (' + unit + ')', data: Array(chartData.length).fill(parseFloat(getElement("goalWeight").value)), borderColor: 'var(–success-color)', borderDash: [5, 5], fill: false } ] }, options: { responsive: true, maintainAspectRatio: false, scales: { y: { beginAtZero: false, title: { display: true, text: 'Weight (' + unit + ')' } }, x: { title: { display: true, text: 'Time' } } }, plugins: { tooltip: { callbacks: { title: function(tooltipItems) { var label = tooltipItems[0].label; if (label.startsWith('W')) { return `Week ${label.substring(1)}`; } return label; }, label: function(context) { var label = context.dataset.label || "; if (label) { label += ': '; } if (context.parsed.y !== null) { label += context.parsed.y.toFixed(2); } return label; } } } } } }); } function resetForm() { getElement("currentWeight").value = ""; getElement("goalWeight").value = ""; getElement("currentWeightDate").value = ""; getElement("goalWeightDate").value = ""; getElement("weeklyWeightLossRate").value = ""; getElement("weightUnit").value = "kg"; getElement("results").style.display = 'none'; getElement("currentWeightError").style.display = 'none'; getElement("goalWeightError").style.display = 'none'; getElement("currentWeightDateError").style.display = 'none'; getElement("goalWeightDateError").style.display = 'none'; getElement("weeklyWeightLossRateError").style.display = 'none'; getElement("currentWeight").style.borderColor = '#ccc'; getElement("goalWeight").style.borderColor = '#ccc'; getElement("currentWeightDate").style.borderColor = '#ccc'; getElement("goalWeightDate").style.borderColor = '#ccc'; getElement("weeklyWeightLossRate").style.borderColor = '#ccc'; // Destroy chart if it exists if (chartInstance) { chartInstance.destroy(); chartInstance = null; } getElement("weightLossChart").getContext("2d").clearRect(0, 0, getElement("weightLossChart").width, getElement("weightLossChart").height); getElement("tableBody").innerHTML = ""; // Clear table } function copyResults() { var primaryResult = getElement("primaryResult").textContent; var totalWeightToLose = getElement("totalWeightToLose").textContent; var estimatedWeeksByRate = getElement("estimatedWeeksByRate").textContent; var estimatedWeeksByDates = getElement("estimatedWeeksByDates").textContent; var avgDailyLossRate = getElement("avgDailyLossRate").textContent; var currentWeight = getElement("currentWeight").value; var goalWeight = getElement("goalWeight").value; var currentDate = getElement("currentWeightDate").value; var goalDate = getElement("goalWeightDate").value; var weeklyRate = getElement("weeklyWeightLossRate").value; var unit = getElement("weightUnit").value; var assumptions = `— Key Assumptions —\nCurrent Weight: ${currentWeight} ${unit}\nGoal Weight: ${goalWeight} ${unit}\nStart Date: ${currentDate}\nTarget Date: ${goalDate}\nDesired Weekly Loss Rate: ${weeklyRate} ${unit}/week\n`; var resultsText = `— Weight Loss Progression Results —\n${getElement("results").querySelector('.result-label').textContent}: ${primaryResult}\nTotal Weight to Lose: ${totalWeightToLose}\nEstimated Weeks to Goal (by Rate): ${estimatedWeeksByRate}\nEstimated Weeks to Goal (by Dates): ${estimatedWeeksByDates}\nAverage Daily Loss Rate: ${avgDailyLossRate}\n\n${assumptions}`; // Use Clipboard API for modern browsers navigator.clipboard.writeText(resultsText).then(function() { alert('Results copied to clipboard!'); }).catch(function(err) { console.error('Failed to copy results: ', err); // Fallback for older browsers or if clipboard API fails var textArea = document.createElement("textarea"); textArea.value = resultsText; textArea.style.position = "fixed"; // Avoid scrolling to bottom textArea.style.left = "-9999px"; textArea.style.top = "-9999px"; document.body.appendChild(textArea); textArea.focus(); textArea.select(); try { var successful = document.execCommand('copy'); var msg = successful ? 'successful' : 'unsuccessful'; alert('Results copied to clipboard!'); } catch (err) { alert('Copying failed. Please copy manually.'); } document.body.removeChild(textArea); }); } // Add event listeners for FAQ toggling document.addEventListener('DOMContentLoaded', function() { var faqQuestions = document.querySelectorAll('.faq-question'); faqQuestions.forEach(function(question) { question.addEventListener('click', function() { var answer = this.nextElementSibling; if (answer.style.display === 'block') { answer.style.display = 'none'; } else { answer.style.display = 'block'; } }); }); // Initial calculation on load if inputs are pre-filled (e.g., from session storage) if (getElement("currentWeight").value && getElement("goalWeight").value && getElement("currentWeightDate").value && getElement("goalWeightDate").value && getElement("weeklyWeightLossRate").value) { calculateWeightLoss(); } }); // Include Chart.js library directly for demonstration purposes. In a real-world scenario, // you'd typically include this via a CDN script tag in the head or manage dependencies. // For this self-contained HTML file, we embed a simplified version. // NOTE: This is a placeholder and would need the actual Chart.js library included. // For a fully functional, self-contained HTML, you'd ideally have the Chart.js library script tag. // Since direct embedding is complex and usually done via CDN, we rely on the assumption // that Chart.js is available in the environment where this HTML is rendered or linked. // If running this standalone, you MUST include the Chart.js CDN link in the . // Example:

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