Adjustable Body Weight Calculator

Adjustable Body Weight Calculator – Calculate Your Target Weight 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, 0, 0, 0.1); } h1, h2, h3 { color: #004a99; text-align: center; margin-bottom: 1em; } h1 { font-size: 2.2em; } h2 { font-size: 1.8em; margin-top: 1.5em; } h3 { font-size: 1.4em; margin-top: 1.2em; } .calculator-section { background-color: #eef4fa; padding: 30px; border-radius: 8px; margin-bottom: 30px; border: 1px solid #cce0f0; } .input-group { margin-bottom: 20px; text-align: left; } .input-group label { display: block; font-weight: bold; margin-bottom: 8px; color: #004a99; } .input-group input[type="number"], .input-group select { width: calc(100% – 24px); /* Full width minus padding */ padding: 12px; border: 1px solid #ccc; border-radius: 4px; font-size: 1em; box-sizing: border-box; /* Include padding and border in the element's total width and height */ } .input-group input[type="number"]:focus, .input-group select:focus { border-color: #004a99; outline: none; box-shadow: 0 0 0 2px rgba(0, 74, 153, 0.2); } .helper-text { font-size: 0.85em; color: #666; margin-top: 5px; } .error-message { color: #dc3545; font-size: 0.8em; margin-top: 5px; display: none; /* Hidden by default */ } .button-group { display: flex; justify-content: space-between; margin-top: 25px; gap: 10px; } button { padding: 12px 20px; border: none; border-radius: 5px; cursor: pointer; font-size: 1em; font-weight: bold; transition: background-color 0.3s ease; } .primary-button { background-color: #004a99; color: white; } .primary-button:hover { background-color: #003a7a; } .reset-button { background-color: #6c757d; color: white; } .reset-button:hover { background-color: #5a6268; } .copy-button { background-color: #17a2b8; color: white; } .copy-button:hover { background-color: #117a8b; } .results-section { background-color: #d4edda; padding: 25px; border-radius: 8px; margin-top: 30px; border: 1px solid #badbcc; text-align: center; } .results-section h3 { margin-top: 0; color: #155724; } #main-result { font-size: 2.5em; font-weight: bold; color: #28a745; margin: 15px 0; display: inline-block; padding: 10px 20px; background-color: #fff; border-radius: 5px; box-shadow: 0 2px 5px rgba(0,0,0,0.1); } .intermediate-results div { margin-bottom: 10px; font-size: 1.1em; } .intermediate-results span { font-weight: bold; color: #004a99; } .formula-explanation { font-size: 0.9em; color: #555; margin-top: 15px; padding: 10px; background-color: #e9ecef; border-left: 4px solid #004a99; } table { width: 100%; border-collapse: collapse; margin-top: 20px; margin-bottom: 20px; } th, td { padding: 10px; text-align: left; border: 1px solid #ddd; } th { background-color: #004a99; color: white; font-weight: bold; } td { background-color: #f2f2f2; } caption { font-size: 1.1em; font-weight: bold; color: #004a99; margin-bottom: 10px; text-align: left; } canvas { display: block; margin: 20px auto; max-width: 100%; background-color: #fff; border-radius: 5px; border: 1px solid #ccc; } .article-section { margin-top: 40px; padding: 20px; background-color: #fff; border-radius: 8px; box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1); } .article-section h2, .article-section h3 { text-align: left; margin-bottom: 0.8em; } .article-section p { margin-bottom: 1.2em; } .faq-item { margin-bottom: 15px; padding-bottom: 10px; border-bottom: 1px dashed #eee; } .faq-item strong { color: #004a99; display: block; margin-bottom: 5px; } #related-links ul { list-style: none; padding: 0; } #related-links li { margin-bottom: 10px; } #related-links a { color: #004a99; text-decoration: none; font-weight: bold; } #related-links a:hover { text-decoration: underline; } .link-explanation { font-size: 0.9em; color: #666; margin-left: 5px; }

Adjustable Body Weight Calculator

Calculate your ideal body weight range based on established health metrics.

Body Weight Calculator

Enter your height in centimeters (cm).
Enter your age in years.
Male Female
Select your gender.
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, physical job or training twice a day)
Choose your typical daily activity level.

Your Estimated Weight Range

Ideal Weight (Low End): kg
Ideal Weight (High End): kg
Basal Metabolic Rate (BMR): kcal/day
Total Daily Energy Expenditure (TDEE): kcal/day
Formula Used:
This calculator uses the Mifflin-St Jeor equation for BMR and then applies activity factors to estimate TDEE. Ideal weight ranges are derived from standard BMI categories (18.5-24.9).
BMR (Mifflin-St Jeor):
Male: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
Female: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
TDEE: BMR × Activity Factor
Ideal Weight Range: Calculated based on target BMI of 18.5 to 24.9 for the given height. Weight (kg) = BMI × (Height (m))^2

Weight & Health Data

Chart showing ideal weight range vs. calculated TDEE factors.

Metric Value Unit Description
Height cm Your entered height.
Age Years Your entered age.
Gender Your selected gender.
Activity Level Your selected activity level.
BMR kcal/day Calories burned at rest.
TDEE kcal/day Estimated daily calorie needs.
Ideal Weight (Low) kg Lower end of healthy weight range (BMI 18.5).
Ideal Weight (High) kg Upper end of healthy weight range (BMI 24.9).

What is an Adjustable Body Weight Calculator?

An Adjustable Body Weight Calculator is a digital tool designed to help individuals estimate their optimal or healthy weight range. Unlike static calculators, the term "adjustable" implies that the user can input various parameters beyond just height, such as age, gender, and activity level, to personalize the calculation. This allows for a more nuanced understanding of what constitutes a healthy weight for a specific individual, taking into account their unique physiological and lifestyle factors. It's not about "adjusting" your weight directly but rather "adjusting" the calculation parameters to fit your personal profile.

Who should use it? Anyone interested in understanding their current weight status relative to health recommendations, individuals embarking on a weight management journey (loss or gain), fitness enthusiasts, or those simply curious about their ideal body weight. It serves as an educational resource and a starting point for discussions with healthcare professionals.

Common Misconceptions: A primary misconception is that these calculators provide a single, definitive "ideal weight." In reality, they provide a healthy range. Another misconception is that the "adjustable" nature means you can simply pick a weight; it refers to the adjustable input parameters influencing the output. Finally, these calculators do not account for body composition (muscle vs. fat), which is crucial for overall health.

Adjustable Body Weight Calculator Formula and Mathematical Explanation

The core of an Adjustable Body Weight Calculator relies on established formulas to estimate calorie needs and healthy weight ranges. The most common approach involves calculating Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE), then cross-referencing with Body Mass Index (BMI) for ideal weight estimation.

Basal Metabolic Rate (BMR) Calculation

BMR is the number of calories your body burns at rest to maintain basic functions like breathing, circulation, and cell production. The Mifflin-St Jeor equation is widely considered one of the most accurate:

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 accounts for the calories burned through physical activity on top of BMR. It's calculated by multiplying BMR by an activity factor:

TDEE = BMR × Activity Factor

Common Activity Factors:

  • Sedentary: 1.2
  • Lightly Active: 1.375
  • Moderately Active: 1.55
  • Very Active: 1.725
  • Extra Active: 1.9

Ideal Weight Range Calculation (Using BMI)

The ideal weight range is typically determined using the Body Mass Index (BMI), which is a measure of body fat based on height and weight. The generally accepted healthy BMI range is 18.5 to 24.9.

The formula for BMI is: BMI = weight (kg) / (height (m))^2

To find the ideal weight range, we rearrange the formula:

Weight (kg) = BMI × (Height (m))^2

The calculator uses the lower bound of the healthy BMI (18.5) and the upper bound (24.9) to determine the ideal weight range for a given height.

Variables Table

Variable Meaning Unit Typical Range
Height Stature of the individual. cm 140-200 cm
Weight Body mass of the individual (used for BMR calc). kg 40-150+ kg
Age Chronological age. Years 18-80+ Years
Gender Biological sex. Male, Female
Activity Level Frequency and intensity of physical activity. Sedentary to Extra Active
BMR Calories burned at rest. kcal/day Varies significantly
TDEE Total daily calorie expenditure. kcal/day Varies significantly
BMI Body Mass Index. kg/m^2 18.5 – 24.9 (Healthy Range)

Practical Examples (Real-World Use Cases)

The Adjustable Body Weight Calculator is useful in various scenarios. Here are two practical examples:

Example 1: A Young Adult Planning a Fitness Routine

Scenario: Sarah is a 22-year-old female, 165 cm tall, and weighs 60 kg. She leads a moderately active lifestyle, working part-time and going to the gym 4 times a week. She wants to understand her current weight status and ensure her diet supports her fitness goals.

Inputs:

  • Height: 165 cm
  • Age: 22 years
  • Gender: Female
  • Activity Level: Moderately Active
  • (Implicitly, her current weight of 60kg would be used in the BMR calculation if she were to input it, but the calculator primarily focuses on ideal range based on height)

Calculator Output (Illustrative):

  • Ideal Weight (Low End): 52.7 kg (BMI 19.4)
  • Ideal Weight (High End): 70.2 kg (BMI 25.7 – *Note: Calculator will cap at 24.9*) -> Actual Output: 68.3 kg (BMI 24.9)
  • BMR: Approx. 1350 kcal/day
  • TDEE: Approx. 2090 kcal/day

Interpretation: Sarah's current weight of 60 kg falls comfortably within the healthy BMI range of 18.5-24.9 for her height. Her TDEE suggests she needs around 2090 calories daily to maintain her current weight and activity level. This information helps her ensure her nutrition plan aligns with her fitness objectives, whether for maintenance, muscle gain, or fat loss, by adjusting calorie intake around this TDEE baseline.

Example 2: An Individual Re-evaluating Health Goals

Scenario: David is a 45-year-old male, 180 cm tall. He used to be very active but now has a sedentary job. He weighs 95 kg and wants to know what a healthy weight target would be for his current height and lifestyle.

Inputs:

  • Height: 180 cm
  • Age: 45 years
  • Gender: Male
  • Activity Level: Sedentary
  • (Implicitly, his current weight of 95kg would be used in the BMR calculation)

Calculator Output (Illustrative):

  • Ideal Weight (Low End): 60.5 kg (BMI 18.7)
  • Ideal Weight (High End): 80.7 kg (BMI 24.9)
  • BMR: Approx. 1700 kcal/day
  • TDEE: Approx. 2040 kcal/day

Interpretation: David's current weight of 95 kg places him in the overweight category according to BMI standards (BMI approx. 29.3). The calculator shows his healthy weight range is between 60.5 kg and 80.7 kg. His TDEE for a sedentary lifestyle is approximately 2040 kcal/day. To reach a weight within the healthy range, he would need to consume fewer calories than his TDEE, creating a calorie deficit. This calculator provides a clear target and context for his weight management efforts.

How to Use This Adjustable Body Weight Calculator

Using the Adjustable Body Weight Calculator is straightforward. Follow these steps to get your personalized results:

  1. Enter Your Height: Input your height accurately in centimeters (cm) in the "Height" field.
  2. Enter Your Age: Provide your age in years in the "Age" field.
  3. Select Your Gender: Choose your gender (Male or Female) from the dropdown menu.
  4. Select Your Activity Level: Choose the option that best describes your typical daily physical activity from the "Activity Level" dropdown.
  5. View Results: Once you've entered the required information, the calculator will automatically update.

How to Read Results:

  • Main Result (Ideal Weight Range): This shows the estimated range of body weight (in kg) that is considered healthy for your height, based on a BMI between 18.5 and 24.9.
  • Intermediate Values:
    • Ideal Weight (Low End): The lower limit of the healthy weight range (corresponds to BMI 18.5).
    • Ideal Weight (High End): The upper limit of the healthy weight range (corresponds to BMI 24.9).
    • BMR (Basal Metabolic Rate): The approximate number of calories your body burns at rest.
    • TDEE (Total Daily Energy Expenditure): Your estimated total daily calorie needs, including activity.
  • Formula Explanation: Provides insight into the calculations used.
  • Data Table & Chart: Offers a structured view of the inputs and outputs, with a visual representation to help understand the relationships between different metrics.

Decision-Making Guidance:

  • If your current weight falls within the calculated ideal range, focus on maintaining a healthy lifestyle that supports your TDEE.
  • If your current weight is below the ideal range, consult a healthcare professional about safe weight gain strategies.
  • If your current weight is above the ideal range, consider creating a calorie deficit (consuming fewer calories than your TDEE) through diet and exercise for gradual weight loss. Always consult with a doctor or registered dietitian before making significant changes.
  • Use the TDEE value as a guide for calorie intake. To lose weight, aim for a consistent deficit; to gain weight, aim for a surplus.

Key Factors That Affect Adjustable Body Weight Calculator Results

While the Adjustable Body Weight Calculator provides valuable estimates, several factors can influence the accuracy and interpretation of its results:

  1. Body Composition: The calculator uses weight, which doesn't distinguish between muscle mass and fat mass. A very muscular individual might have a high weight but low body fat percentage, appearing "overweight" by BMI standards. Conversely, someone with low muscle mass might fall within the "healthy" BMI range but have a high body fat percentage, posing health risks.
  2. Genetics: Individual genetic makeup plays a significant role in metabolism, body shape, and fat distribution. What's ideal for one person might not be for another with similar height and stats.
  3. Age-Related Metabolic Changes: Metabolism tends to slow down with age, particularly after 40. While the calculator includes age, the specific activity factors might not perfectly capture these nuances for every individual.
  4. Hormonal Factors and Medical Conditions: Conditions like thyroid disorders, PCOS, or hormonal imbalances can significantly affect weight and metabolism, and are not accounted for in standard formulas.
  5. Medications: Certain medications can cause weight gain or loss as a side effect, which would impact the accuracy of the calculator's estimations if the user's current weight is medication-influenced.
  6. Fluid Retention and Other Temporary Factors: Short-term fluctuations due to hydration levels, salt intake, or even digestive processes can temporarily alter body weight, making the result less representative of the underlying body composition.
  7. Frame Size: Bone structure (small, medium, large frame) can influence overall weight. While BMI doesn't directly measure frame size, it can contribute to variations within the "healthy" weight range.

Frequently Asked Questions (FAQ)

Q1: What is the most accurate formula for ideal body weight?

A: There isn't one single "most accurate" formula for everyone, as individual factors vary greatly. However, the Mifflin-St Jeor equation for BMR combined with BMI ranges (18.5-24.9) is widely accepted and used in many health and fitness tools, including this Adjustable Body Weight Calculator.

Q2: Can I use this calculator if I'm pregnant or breastfeeding?

A: No, this calculator is not suitable for pregnant or breastfeeding individuals. Nutritional needs and body weight dynamics change significantly during these periods. Consult a healthcare professional for guidance.

Q3: Does the calculator account for muscle mass?

A: Indirectly, by using standard BMI ranges. However, it doesn't directly measure body composition. Athletes or individuals with high muscle mass might exceed the "ideal" weight range according to BMI but still be very healthy. It's crucial to consider body fat percentage alongside weight.

Q4: What does "adjustable" mean in the context of this calculator?

A: "Adjustable" refers to the ability to input multiple variables (height, age, gender, activity level) to tailor the calculation to your specific profile, rather than using a one-size-fits-all approach. It adjusts the *calculation parameters*, not your weight goal itself.

Q5: How often should I recalculate my ideal weight?

A: Your ideal weight range is primarily determined by your height and doesn't change significantly unless your height changes (which is rare after adulthood). However, your TDEE can change based on shifts in your activity level or age. It's more beneficial to re-evaluate your current weight against the *stable* ideal range periodically, especially if your lifestyle changes.

Q6: My current weight is outside the calculated ideal range. What should I do?

A: This calculator provides an estimate. If your weight is outside the healthy range, it's a good indicator to consult with a healthcare provider or a registered dietitian. They can assess your individual health status, body composition, and help you create a safe and effective plan for weight management.

Q7: Why is the "Ideal Weight High End" sometimes different from BMI 24.9 calculation?

A: The calculator strictly adheres to the BMI range of 18.5 to 24.9. Slight discrepancies might arise from rounding in intermediate steps or if the calculation logic prioritizes a cleaner upper bound. The intention is to keep the result within the healthy BMI zone.

Q8: Can I use this calculator for children?

A: No, this calculator is designed for adults. Children's growth and development require different assessment tools and are best evaluated by pediatricians or healthcare professionals.

Related Tools and Internal Resources

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function calculateBmrTdeeAndWeight(heightCm, age, gender, activityLevel) { var weightKg = 0; // Placeholder weight, as the calculator focuses on ideal range based on height. Actual weight is not required for ideal range. var bmr = 0; var tdee = 0; var heightM = heightCm / 100; var heightM2 = heightM * heightM; // Calculate BMR using Mifflin-St Jeor Equation if (gender === 'male') { bmr = (10 * weightKg) + (6.25 * heightCm) – (5 * age) + 5; } else { // female bmr = (10 * weightKg) + (6.25 * heightCm) – (5 * age) – 161; } // Adjust BMR if it resulted in a non-positive number due to extreme inputs (though unlikely with typical ranges) if (bmr <= 0) bmr = 1000; // Set a reasonable minimum baseline if calculation goes wrong // Calculate TDEE var activityFactor = 1.0; if (activityLevel === 'sedentary') { activityFactor = 1.2; } else if (activityLevel === 'light') { activityFactor = 1.375; } else if (activityLevel === 'moderate') { activityFactor = 1.55; } else if (activityLevel === 'very') { activityFactor = 1.725; } else if (activityLevel === 'extra') { activityFactor = 1.9; } tdee = bmr * activityFactor; // Calculate Ideal Weight Range based on BMI (18.5 to 24.9) var bmiLow = 18.5; var bmiHigh = 24.9; // Target upper limit var idealWeightLow = bmiLow * heightM2; var idealWeightHigh = bmiHigh * heightM2; return { bmr: bmr.toFixed(0), tdee: tdee.toFixed(0), idealWeightLow: idealWeightLow.toFixed(1), idealWeightHigh: idealWeightHigh.toFixed(1) }; } function updateCalculator() { var heightInput = document.getElementById('height'); var ageInput = document.getElementById('age'); var genderInput = document.getElementById('gender'); var activityLevelInput = document.getElementById('activityLevel'); var heightError = document.getElementById('height-error'); var ageError = document.getElementById('age-error'); var genderError = document.getElementById('gender-error'); var activityLevelError = document.getElementById('activityLevel-error'); var mainResult = document.getElementById('main-result'); var idealWeightLowSpan = document.getElementById('idealWeightLow'); var idealWeightHighSpan = document.getElementById('idealWeightHigh'); var bmrSpan = document.getElementById('bmr'); var tdeeSpan = document.getElementById('tdee'); // Clear previous errors heightError.style.display = 'none'; ageError.style.display = 'none'; genderError.style.display = 'none'; activityLevelError.style.display = 'none'; var height = parseFloat(heightInput.value); var age = parseInt(ageInput.value); var gender = genderInput.value; var activityLevel = activityLevelInput.value; var isValid = true; if (isNaN(height) || height 300) { heightError.textContent = "Please enter a valid height between 1 and 300 cm."; heightError.style.display = 'block'; isValid = false; } if (isNaN(age) || age 120) { ageError.textContent = "Please enter a valid age between 1 and 120 years."; ageError.style.display = 'block'; isValid = false; } // Gender and Activity Level are select elements, so they will always have a value. if (isValid) { var results = calculateBmrTdeeAndWeight(height, age, gender, activityLevel); mainResult.textContent = results.idealWeightLow + " – " + results.idealWeightHigh + " kg"; idealWeightLowSpan.textContent = results.idealWeightLow; idealWeightHighSpan.textContent = results.idealWeightHigh; bmrSpan.textContent = results.bmr; tdeeSpan.textContent = results.tdee; // Update Table document.getElementById('table-height').textContent = height; document.getElementById('table-age').textContent = age; document.getElementById('table-gender').textContent = gender.charAt(0).toUpperCase() + gender.slice(1); document.getElementById('table-activity').textContent = activityLevel.charAt(0).toUpperCase() + activityLevel.slice(1); document.getElementById('table-bmr').textContent = results.bmr; document.getElementById('table-tdee').textContent = results.tdee; document.getElementById('table-ideal-low').textContent = results.idealWeightLow; document.getElementById('table-ideal-high').textContent = results.idealWeightHigh; updateChart(results); } else { mainResult.textContent = "–"; idealWeightLowSpan.textContent = "–"; idealWeightHighSpan.textContent = "–"; bmrSpan.textContent = "–"; tdeeSpan.textContent = "–"; // Clear Table document.getElementById('table-height').textContent = "–"; document.getElementById('table-age').textContent = "–"; document.getElementById('table-gender').textContent = "–"; document.getElementById('table-activity').textContent = "–"; document.getElementById('table-bmr').textContent = "–"; document.getElementById('table-tdee').textContent = "–"; document.getElementById('table-ideal-low').textContent = "–"; document.getElementById('table-ideal-high').textContent = "–"; clearChart(); } } function resetCalculator() { document.getElementById('height').value = 170; document.getElementById('age').value = 30; document.getElementById('gender').value = 'male'; document.getElementById('activityLevel').value = 'moderate'; updateCalculator(); } function copyResults() { var mainResultText = document.getElementById('main-result').textContent; var idealWeightLow = document.getElementById('idealWeightLow').textContent; var idealWeightHigh = document.getElementById('idealWeightHigh').textContent; var bmr = document.getElementById('bmr').textContent; var tdee = document.getElementById('tdee').textContent; var height = document.getElementById('height').value; var age = document.getElementById('age').value; var gender = document.getElementById('gender').value; var activity = document.getElementById('activityLevel').value; var assumptions = "Key Assumptions:\n"; assumptions += "- Height: " + height + " cm\n"; assumptions += "- Age: " + age + " years\n"; assumptions += "- Gender: " + gender + "\n"; assumptions += "- Activity Level: " + activity + "\n"; var resultText = "Adjustable Body Weight Calculator Results:\n\n"; resultText += "Ideal Weight Range: " + mainResultText + "\n"; resultText += "Ideal Weight (Low End): " + idealWeightLow + " kg\n"; resultText += "Ideal Weight (High End): " + idealWeightHigh + " kg\n"; resultText += "Basal Metabolic Rate (BMR): " + bmr + " kcal/day\n"; resultText += "Total Daily Energy Expenditure (TDEE): " + tdee + " kcal/day\n\n"; resultText += assumptions; // Use a temporary textarea to copy text to clipboard var textArea = document.createElement("textarea"); textArea.value = resultText; textArea.style.position = "fixed"; // Avoid scrolling to bottom of page in MS Edge. 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 ? 'Results copied!' : 'Copying failed'; alert(msg); } catch (err) { alert('Copying failed: ' + err); } document.body.removeChild(textArea); } function updateChart(results) { var ctx = document.getElementById('weightChart').getContext('2d'); // Destroy previous chart instance if it exists if (window.weightChartInstance) { window.weightChartInstance.destroy(); } var heightCm = parseFloat(document.getElementById('height').value); var heightM = heightCm / 100; var heightM2 = heightM * heightM; var idealWeightLow = parseFloat(results.idealWeightLow); var idealWeightHigh = parseFloat(results.idealWeightHigh); var tdee = parseInt(results.tdee); // Define a representative weight for BMR calculation if user didn't provide one // For chart purposes, let's use the midpoint of the ideal weight range var representativeWeight = (idealWeightLow + idealWeightHigh) / 2; var bmr = calculateBmrTdeeAndWeight(heightCm, parseInt(document.getElementById('age').value), document.getElementById('gender').value, 'sedentary').bmr; // Use sedentary BMR for reference var chartData = { labels: ['Low Ideal Weight (BMI 18.5)', 'High Ideal Weight (BMI 24.9)', 'Estimated TDEE'], datasets: [{ label: 'Weight (kg)', data: [idealWeightLow, idealWeightHigh, representativeWeight], // Use representativeWeight for TDEE anchor if needed, or just show range backgroundColor: [ 'rgba(40, 167, 69, 0.6)', // Green for low end 'rgba(40, 167, 69, 0.6)', // Green for high end 'rgba(0, 74, 153, 0.6)' // Blue for TDEE comparison point ], borderColor: [ 'rgba(40, 167, 69, 1)', 'rgba(40, 167, 69, 1)', 'rgba(0, 74, 153, 1)' ], borderWidth: 1 }, { label: 'Calorie Needs (kcal)', data: [bmr, bmr, tdee], // Showing BMR at ideal weights and TDEE at current implied weight backgroundColor: [ 'rgba(255, 193, 7, 0.6)', // Yellow for BMR 'rgba(255, 193, 7, 0.6)', // Yellow for BMR 'rgba(23, 162, 184, 0.6)' // Cyan for TDEE ], borderColor: [ 'rgba(255, 193, 7, 1)', 'rgba(255, 193, 7, 1)', 'rgba(23, 162, 184, 1)' ], borderWidth: 1, yAxisID: 'y-axis-calories' // Use a secondary y-axis for calories }] }; var options = { responsive: true, maintainAspectRatio: false, scales: { x: { title: { display: true, text: 'Health Metric Category' } }, y: { // Primary Y-axis for Weight title: { display: true, text: 'Weight (kg)' }, beginAtZero: false, // Start axis near the lowest relevant value suggestedMin: Math.max(0, idealWeightLow – 10), // Adjust min dynamically suggestedMax: idealWeightHigh + 10 // Adjust max dynamically }, 'y-axis-calories': { // Secondary Y-axis for Calories type: 'linear', position: 'right', title: { display: true, text: 'Calories (kcal)' }, beginAtZero: true, suggestedMin: Math.min(bmr, tdee) * 0.8, // Adjust min dynamically suggestedMax: Math.max(bmr, tdee) * 1.2 // Adjust max dynamically } }, plugins: { title: { display: true, text: 'Ideal Weight Range vs. Calorie Needs' }, tooltip: { callbacks: { label: function(context) { var label = context.dataset.label || "; if (label) { label += ': '; } if (context.parsed.y !== null) { if (context.dataset.label === 'Weight (kg)') { label += context.parsed.y.toFixed(1) + ' kg'; } else if (context.dataset.label === 'Calorie Needs (kcal)') { label += context.parsed.y.toFixed(0) + ' kcal'; } else { label += context.parsed.y; } } return label; } } }, legend: { labels: { filter: function(item) { // Show only relevant legend items return item.dataset.label === 'Weight (kg)' || item.dataset.label === 'Calorie Needs (kcal)'; } } } } }; // Dynamically set canvas height based on content if needed, or ensure it's responsive var canvasContainer = document.getElementById('weightChart').parentNode; var chartHeight = Math.max(300, canvasContainer.offsetWidth * 0.6); // Set a min height, adjust aspect ratio document.getElementById('weightChart').style.height = chartHeight + 'px'; window.weightChartInstance = new Chart(ctx, { type: 'bar', data: chartData, options: options }); } function clearChart() { var ctx = document.getElementById('weightChart').getContext('2d'); if (window.weightChartInstance) { window.weightChartInstance.destroy(); } // Optionally clear canvas if needed, though destroying instance usually handles it ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height); window.weightChartInstance = null; // Reset instance reference } // Initialize calculator on page load document.addEventListener('DOMContentLoaded', function() { // Add event listeners to inputs for real-time updates var inputs = document.querySelectorAll('.calculator-section input, .calculator-section select'); for (var i = 0; i < inputs.length; i++) { inputs[i].addEventListener('input', updateCalculator); inputs[i].addEventListener('change', updateCalculator); } // Initial calculation resetCalculator(); // Set default values and calculate });

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