Calculator for Calories per Day to Lose Weight

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Calories Per Day to Lose Weight Calculator

Determine your ideal daily calorie intake for healthy and sustainable weight loss.

Weight Loss Calorie Calculator

Enter your weight in kilograms (kg).
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/sports & physical job) Choose your typical weekly physical activity.
Enter your desired weight loss in kilograms (kg).
Slow (0.25 kg/week) Moderate (0.5 kg/week) Fast (0.75 kg/week) Very Fast (1 kg/week) How quickly do you want to lose weight? (0.5 kg/week is generally recommended)

Your Weight Loss Plan

0 kcal
BMR0 kcal
TDEE0 kcal
Weekly Deficit0 kcal

Your daily calorie target is calculated by first determining your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, then multiplying by your activity level to get your Total Daily Energy Expenditure (TDEE). Finally, a calorie deficit is subtracted from your TDEE to achieve your desired weight loss rate.

Estimated Daily Calorie Intake Over Time
Metabolic Rate & Calorie Deficit Overview
Metric Value Unit
Basal Metabolic Rate (BMR) 0 kcal/day
Total Daily Energy Expenditure (TDEE) 0 kcal/day
Required Weekly Calorie Deficit 0 kcal/week
Target Daily Calorie Intake 0 kcal/day
Estimated Time to Reach Goal 0 weeks

What is Calories Per Day to Lose Weight?

The concept of "calories per day to lose weight" is fundamental to understanding and achieving successful weight management. It refers to the specific, calculated daily energy intake that creates a calorie deficit, prompting your body to burn stored fat for fuel. Essentially, it's the number of calories you should consume each day to progressively reduce your body weight over a given period. This isn't about drastic deprivation but a strategic approach based on your unique metabolic needs and activity levels. Understanding your personalized calorie target is the cornerstone of any effective weight loss journey, moving beyond generic advice to actionable, data-driven planning.

Who Should Use It?

Anyone looking to lose weight in a healthy, sustainable manner can benefit from calculating their target daily calories. This includes:

  • Individuals aiming for gradual, consistent weight loss rather than rapid, unsustainable drops.
  • People who want to understand the scientific basis behind their weight management efforts.
  • Those who have struggled with dieting in the past and need a more personalized approach.
  • Individuals seeking to maintain their current weight after achieving their loss goals.
  • Fitness enthusiasts looking to optimize their body composition.

Common Misconceptions

Several myths surround calorie counting for weight loss. A common misconception is that all calories are equal; while a calorie is a unit of energy, the source of those calories (e.g., whole foods vs. processed snacks) impacts satiety, nutrient intake, and hormonal responses. Another myth is that you need to eat extremely low calories to lose weight. In reality, drastically cutting calories can slow metabolism and be unsustainable. The focus should be on a moderate deficit derived from nutrient-dense foods. Finally, many believe weight loss is purely about willpower, neglecting the crucial role of metabolic rate, genetics, and hormonal factors, all of which are addressed by calculating specific calorie needs.

Calories Per Day to Lose Weight Formula and Mathematical Explanation

Calculating your daily calorie target for weight loss involves a multi-step process rooted in understanding your body's energy expenditure. The most widely accepted method uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), followed by an adjustment for your daily activity level to determine your Total Daily Energy Expenditure (TDEE). Finally, a targeted calorie deficit is applied to TDEE to facilitate weight loss.

Step 1: Calculate Basal Metabolic Rate (BMR)

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 considered more accurate than older formulas. The formulas are:

  • 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

Step 2: Calculate Total Daily Energy Expenditure (TDEE)

TDEE accounts for the calories burned through physical activity and the thermic effect of food. It's calculated by multiplying your BMR by an appropriate activity factor:

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

Step 3: Determine Calorie Deficit for Weight Loss

To lose weight, you need to consume fewer calories than your TDEE. A deficit of approximately 3,500 calories is generally needed to lose one pound (about 0.45 kg) of fat. To achieve a desired weekly loss rate:

  • Weight Loss in kg per week * 7700 kcal/kg = Required weekly calorie deficit
  • (Required weekly calorie deficit) / 7 days = Target daily calorie deficit

Your target daily calorie intake for weight loss is then:

Target Daily Calories = TDEE – Target daily calorie deficit

Variables Table

Variable Meaning Unit Typical Range
Current Weight Your current body mass. Kilograms (kg) 20 – 500+ kg
Height Your body height. Centimeters (cm) 50 – 250 cm
Age Your age in years. Years 1 – 120 years
Gender Biological sex, affecting metabolic rate. Male / Female N/A
Activity Level Frequency and intensity of physical activity. Categorical Sedentary to Extra Active
Weight Loss Goal Total amount of weight to lose. Kilograms (kg) 0.5 – 200+ kg
Desired Loss Rate Rate of weight loss per week. Kilograms (kg)/week 0.25 – 1.0 kg/week (recommended max 0.5-1.0)
BMR Calories burned at rest. kcal/day Varies greatly based on inputs
TDEE Total daily calories burned. kcal/day Varies greatly based on inputs
Target Daily Calorie Intake Recommended daily calorie consumption for weight loss. kcal/day Varies greatly based on inputs

Practical Examples (Real-World Use Cases)

Example 1: Sarah, aiming for moderate weight loss

Sarah is a 30-year-old female, 165 cm tall, weighing 70 kg. She works a desk job but goes for brisk walks 3-4 times a week. She wants to lose 5 kg at a moderate pace.

  • Inputs: Current Weight: 70 kg, Height: 165 cm, Age: 30, Gender: Female, Activity Level: Lightly Active, Weight Loss Goal: 5 kg, Desired Loss Rate: 0.5 kg/week.
  • Calculation:
    • BMR (Female) = (10 * 70) + (6.25 * 165) – (5 * 30) – 161 = 700 + 1031.25 – 150 – 161 = 1420.25 kcal
    • TDEE (Lightly Active) = 1420.25 * 1.375 = 1952.84 kcal
    • Required Weekly Deficit for 0.5 kg loss = 0.5 kg * 7700 kcal/kg = 3850 kcal/week
    • Target Daily Deficit = 3850 / 7 = 550 kcal/day
    • Target Daily Calorie Intake = 1952.84 – 550 = 1402.84 kcal
  • Results:
    • BMR: ~1420 kcal
    • TDEE: ~1953 kcal
    • Weekly Deficit: ~3850 kcal
    • Target Daily Calorie Intake: ~1403 kcal
  • Interpretation: Sarah should aim to consume approximately 1403 calories per day to lose about 0.5 kg per week. This involves a deficit of around 550 calories from her TDEE.

Example 2: Mark, aiming for faster, but safe, weight loss

Mark is a 45-year-old male, 180 cm tall, weighing 95 kg. He has a moderately active job and exercises intensely 4 times a week. He wants to lose 10 kg fairly quickly, aiming for 0.75 kg per week.

  • Inputs: Current Weight: 95 kg, Height: 180 cm, Age: 45, Gender: Male, Activity Level: Moderately Active, Weight Loss Goal: 10 kg, Desired Loss Rate: 0.75 kg/week.
  • Calculation:
    • BMR (Male) = (10 * 95) + (6.25 * 180) – (5 * 45) + 5 = 950 + 1125 – 225 + 5 = 1855 kcal
    • TDEE (Moderately Active) = 1855 * 1.55 = 2875.25 kcal
    • Required Weekly Deficit for 0.75 kg loss = 0.75 kg * 7700 kcal/kg = 5775 kcal/week
    • Target Daily Deficit = 5775 / 7 = 825 kcal/day
    • Target Daily Calorie Intake = 2875.25 – 825 = 2050.25 kcal
  • Results:
    • BMR: ~1855 kcal
    • TDEE: ~2875 kcal
    • Weekly Deficit: ~5775 kcal
    • Target Daily Calorie Intake: ~2050 kcal
  • Interpretation: Mark should aim for around 2050 calories per day to lose approximately 0.75 kg per week. This is an ambitious but potentially achievable goal for someone with his stats and activity level, provided it's done safely and with nutrient-dense foods. He needs to ensure he's still meeting nutritional needs on this intake.

How to Use This Calories Per Day to Lose Weight Calculator

Our calculator is designed to be intuitive and provide you with personalized calorie targets quickly. Follow these simple steps:

  1. Input Your Details: Enter your current weight (in kg), height (in cm), age (in years), and select your gender.
  2. Select Activity Level: Choose the option that best describes your typical weekly physical activity. Be honest for the most accurate results.
  3. Define Your Goal: Enter the total amount of weight you wish to lose (in kg) and select your desired weekly loss rate. A moderate rate of 0.5 kg per week is generally recommended for sustainability and health.
  4. Calculate: Click the "Calculate Calories" button.

How to Read Your Results

The calculator will display:

  • Primary Result: Your Target Daily Calorie Intake in kilocalories (kcal). This is the number of calories you should aim to consume daily.
  • Intermediate Values: Your estimated Basal Metabolic Rate (BMR) – calories burned at rest – and your Total Daily Energy Expenditure (TDEE) – calories burned including activity. The required weekly and daily calorie deficit is also shown.
  • Table and Chart: A summary table reinforces the key numbers and visually represents your calorie journey over time.

Decision-Making Guidance

Use your calculated target daily calorie intake as a guide. Remember that these are estimates. Listen to your body and adjust as needed. Focus on consuming nutrient-dense foods to ensure you get adequate vitamins and minerals even with a reduced calorie intake. If you're unsure about your calorie target or if you have any underlying health conditions, it's always best to consult with a healthcare professional or a registered dietitian before making significant changes to your diet.

Key Factors That Affect Calories Per Day to Lose Weight Results

While the calculator provides personalized estimates, several crucial factors can influence your actual calorie needs and weight loss journey. Understanding these can help you fine-tune your approach and manage expectations.

1. Metabolic Adaptation

As you lose weight, your body's metabolism can adapt. Your BMR and TDEE may decrease because you have less body mass to support and your body becomes more efficient at conserving energy. This means you might need to gradually adjust your calorie intake downwards as you progress towards your goal to maintain a consistent rate of weight loss. Our calculator provides a starting point; continuous monitoring and potential adjustments are key.

2. Body Composition

Muscle tissue burns more calories at rest than fat tissue. Two individuals with the same weight, height, age, and gender can have different BMRs if their body composition differs significantly. Someone with a higher percentage of lean muscle mass will have a higher BMR. While our calculator doesn't measure body composition directly, understanding this principle highlights the benefits of strength training alongside calorie restriction.

3. Hormonal Factors

Hormones play a significant role in appetite regulation, metabolism, and fat storage. Conditions like thyroid disorders (hypothyroidism or hyperthyroidism), polycystic ovary syndrome (PCOS), and hormonal changes related to menopause can affect your metabolic rate and make weight loss more challenging. If you suspect hormonal issues, consulting a doctor is essential.

4. Genetics

Genetics can influence your predisposition to weight gain, where your body stores fat, and your metabolic rate. Some individuals may naturally have a higher BMR or be more efficient at burning calories, while others may find weight loss inherently more difficult. While you can't change your genes, understanding your genetic tendencies can help you set realistic goals and focus on sustainable lifestyle changes.

5. 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 abdominal fat), and decrease metabolic rate. Prioritizing quality sleep (7-9 hours per night) and managing stress through techniques like mindfulness, meditation, or yoga can significantly support weight loss efforts.

6. Food Quality and Nutrient Timing

While the calculator focuses on calorie quantity, the quality of your calories matters. Nutrient-dense foods (vegetables, fruits, lean proteins, whole grains) provide essential vitamins, minerals, and fiber, promoting satiety and better health. The timing of your meals, while less impactful than overall calorie intake, can also play a role for some individuals in managing hunger and energy levels throughout the day.

7. Medical Conditions and Medications

Certain medical conditions and medications can impact weight and metabolism. For example, some antidepressants, corticosteroids, and diabetes medications can lead to weight gain or make it harder to lose weight. It is crucial to discuss your weight loss goals with your doctor to ensure your plan is safe and compatible with any existing health issues or treatments.

8. Digestive Health

The efficiency of your digestive system can play a role in how well you absorb nutrients and how your body processes food. Factors like gut microbiome balance and digestive enzyme production can indirectly influence metabolism and weight management. A diet rich in fiber from whole foods supports a healthy digestive system.

Frequently Asked Questions (FAQ)

What is the safest rate of weight loss?

Generally, a rate of 0.5 kg to 1 kg (1-2 pounds) per week is considered safe and sustainable for most people. Losing weight faster than this can lead to muscle loss, nutrient deficiencies, gallstones, and other health issues. Our calculator allows you to select rates up to 1 kg/week, but always prioritize health and consult a professional if aiming for higher rates or if you have concerns.

Can I eat whatever I want as long as I stay within my calorie limit?

While staying within your calorie target is crucial for weight loss, the *quality* of those calories matters significantly for overall health, satiety, and nutrient intake. Prioritize whole, unprocessed foods like fruits, vegetables, lean proteins, and whole grains. A diet of only processed foods, even within calorie limits, can lead to nutrient deficiencies and may not keep you feeling full, making it harder to stick to your plan.

My results seem too low/high. Why might this be?

Several factors can influence your individual metabolic rate beyond what a calculator can precisely measure. These include genetics, body composition (muscle vs. fat mass), hormonal balance, and metabolic adaptation from previous dieting. The calculator provides an estimate based on averages. If your results seem significantly off, consider consulting a healthcare professional or registered dietitian for a more personalized assessment.

Do I need to recalculate my calories if I gain muscle?

Yes, if you significantly increase your muscle mass, your BMR and TDEE will likely increase because muscle tissue is metabolically active. You would need to recalculate your calorie needs to reflect your new body composition to maintain your weight or continue losing fat effectively. It's advisable to recalculate periodically, especially after significant changes in your activity or body composition.

How long will it take to reach my weight loss goal?

The estimated time to reach your goal can be calculated. For example, if your goal is 5 kg and you're losing 0.5 kg per week, it would take approximately 10 weeks (5 kg / 0.5 kg/week). The calculator can provide this estimate based on your inputs. Remember this is an approximation; individual results may vary due to adherence, metabolic factors, and other lifestyle influences.

What if I'm exercising a lot? Should I add those calories back?

The activity multiplier in the calculator is designed to account for your typical exercise routine. If you are exercising significantly more than your chosen level, your TDEE might be higher, and thus your target calorie intake could also be higher. Some people prefer to track exercise calories separately and adjust their intake accordingly, but be cautious with this approach as activity trackers are not always perfectly accurate. For simplicity and accuracy, ensure your "Activity Level" reflects your overall lifestyle, including exercise.

Is it okay to go below a certain calorie threshold (e.g., 1200 kcal)?

For most individuals, consuming fewer than 1200 calories per day (for women) or 1500 calories per day (for men) can be difficult to sustain and may not provide adequate nutrients. Very low-calorie diets should generally only be undertaken under strict medical supervision due to the risk of nutrient deficiencies, slowed metabolism, and other health complications. It's usually better to aim for a moderate deficit that allows for a slightly higher calorie intake.

How often should I weigh myself?

Weighing yourself daily can be helpful for tracking trends and understanding how your weight fluctuates due to factors like water retention, but it's not always representative of fat loss. Many experts recommend weighing yourself 1-3 times a week, at the same time of day (e.g., first thing in the morning after using the restroom), to get a more consistent picture. Focus on the overall trend rather than day-to-day changes.

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var calorieChart = document.getElementById("calorieChart"); var chartInstance = null; // Default values var defaultValues = { currentWeight: 70, height: 175, age: 30, gender: "male", activityLevel: "sedentary", weightLossGoal: 5, lossRate: 0.5 }; function validateInput(inputId, errorElementId, min, max) { var input = document.getElementById(inputId); var errorElement = document.getElementById(errorElementId); var value = parseFloat(input.value); errorElement.textContent = ""; input.style.borderColor = "var(–input-border-color)"; if (isNaN(value)) { errorElement.textContent = "Please enter a valid number."; input.style.borderColor = "var(–error-color)"; return false; } if (value < 0) { errorElement.textContent = "Value cannot be negative."; input.style.borderColor = "var(–error-color)"; return false; } if (min !== undefined && value max) { errorElement.textContent = "Value is too high."; input.style.borderColor = "var(–error-color)"; return false; } return true; } function calculateCalories() { var isValid = true; isValid &= validateInput("currentWeight", "currentWeightError", 1); isValid &= validateInput("height", "heightError", 1); isValid &= validateInput("age", "ageError", 1); isValid &= validateInput("weightLossGoal", "weightLossGoalError", 0); var lossRateValue = parseFloat(lossRateInput.value); if (isNaN(lossRateValue) || lossRateValue 1.5) { // Max rate roughly 1.5kg/week for safety bounds document.getElementById("lossRateError").textContent = "Please select a valid rate (e.g., 0.25 to 1.0)."; lossRateInput.style.borderColor = "var(–error-color)"; isValid = false; } else { document.getElementById("lossRateError").textContent = ""; lossRateInput.style.borderColor = "var(–input-border-color)"; } if (!isValid) { resultsSection.style.display = "none"; return; } var currentWeight = parseFloat(currentWeightInput.value); var height = parseFloat(heightInput.value); var age = parseInt(ageInput.value); var gender = genderInput.value; var activityLevel = activityLevelInput.value; var weightLossGoal = parseFloat(weightLossGoalInput.value); var lossRate = parseFloat(lossRateInput.value); var bmr = 0; if (gender === "male") { bmr = (10 * currentWeight) + (6.25 * height) – (5 * age) + 5; } else { bmr = (10 * currentWeight) + (6.25 * height) – (5 * age) – 161; } bmr = Math.round(bmr); var activityMultiplier; switch (activityLevel) { case "sedentary": activityMultiplier = 1.2; break; case "lightlyActive": activityMultiplier = 1.375; break; case "moderatelyActive": activityMultiplier = 1.55; break; case "veryActive": activityMultiplier = 1.725; break; case "extraActive": activityMultiplier = 1.9; break; default: activityMultiplier = 1.2; } var tdee = bmr * activityMultiplier; tdee = Math.round(tdee); var caloriesPerKg = 7700; // Approximate calories in 1 kg of fat var weeklyDeficitNeeded = weightLossGoal * caloriesPerKg; var dailyDeficitTarget = weeklyDeficitNeeded / 7; dailyDeficitTarget = Math.round(dailyDeficitTarget); var targetDailyCalories = tdee – dailyDeficitTarget; // Ensure target is not excessively low, set a minimum reasonable intake (e.g., 1200 kcal) if (targetDailyCalories < 1200) { targetDailyCalories = 1200; // Adjust deficit calculation if we capped target calories dailyDeficitTarget = tdee – targetDailyCalories; weeklyDeficitNeeded = dailyDeficitTarget * 7; } targetDailyCalories = Math.round(targetDailyCalories); var estimatedWeeksToGoal = weightLossGoal / lossRate; // Update results display primaryResult.textContent = targetDailyCalories + " kcal"; bmrResult.textContent = bmr + " kcal"; tdeeResult.textContent = tdee + " kcal"; deficitResult.textContent = dailyDeficitTarget + " kcal"; // Update table tableBmr.textContent = bmr; tableTdee.textContent = tdee; tableDeficit.textContent = dailyDeficitTarget; tableTargetCals.textContent = targetDailyCalories; tableTimeToGoal.textContent = estimatedWeeksToGoal.toFixed(1); // Display with one decimal place resultsSection.style.display = "block"; updateChart(tdee, targetDailyCalories, estimatedWeeksToGoal); } function resetCalculator() { currentWeightInput.value = defaultValues.currentWeight; heightInput.value = defaultValues.height; ageInput.value = defaultValues.age; genderInput.value = defaultValues.gender; activityLevelInput.value = defaultValues.activityLevel; weightLossGoalInput.value = defaultValues.weightLossGoal; lossRateInput.value = defaultValues.lossRate; // Clear errors document.getElementById("currentWeightError").textContent = ""; document.getElementById("heightError").textContent = ""; document.getElementById("ageError").textContent = ""; document.getElementById("genderError").textContent = ""; document.getElementById("activityLevelError").textContent = ""; document.getElementById("weightLossGoalError").textContent = ""; document.getElementById("lossRateError").textContent = ""; // Reset styles currentWeightInput.style.borderColor = "var(–input-border-color)"; heightInput.style.borderColor = "var(–input-border-color)"; ageInput.style.borderColor = "var(–input-border-color)"; weightLossGoalInput.style.borderColor = "var(–input-border-color)"; lossRateInput.style.borderColor = "var(–input-border-color)"; resultsSection.style.display = "none"; if (chartInstance) { chartInstance.destroy(); chartInstance = null; } } function copyResults() { var tdee = Math.round(parseFloat(tdeeResult.textContent)); var targetCals = Math.round(parseFloat(primaryResult.textContent)); var bmr = Math.round(parseFloat(bmrResult.textContent)); var deficit = Math.round(parseFloat(deficitResult.textContent)); var weeksToGoal = parseFloat(tableTimeToGoal.textContent); var assumptions = "Gender: " + genderInput.value + ", Activity Level: " + activityLevelInput.options[activityLevelInput.selectedIndex].text; var goal = "Weight Loss Goal: " + weightLossGoalInput.value + " kg, Desired Loss Rate: " + lossRateInput.options[lossRateInput.selectedIndex].text; var textToCopy = "— Your Weight Loss Plan —\n\n" + "Target Daily Calorie Intake: " + primaryResult.textContent + "\n" + "Basal Metabolic Rate (BMR): " + bmrResult.textContent + "\n" + "Total Daily Energy Expenditure (TDEE): " + tdeeResult.textContent + "\n" + "Daily Calorie Deficit: " + deficitResult.textContent + "\n\n" + "Estimated Weeks to Goal: " + weeksToGoal.toFixed(1) + " weeks\n\n" + "— Key Assumptions —\n" + assumptions + "\n" + goal; if (navigator.clipboard && window.isSecureContext) { navigator.clipboard.writeText(textToCopy).then(function() { alert("Results copied to clipboard!"); }).catch(function(err) { console.error("Failed to copy: ", err); // Fallback for older browsers or non-secure contexts var textArea = document.createElement("textarea"); textArea.value = textToCopy; textArea.style.position = "fixed"; textArea.style.left = "-9999px"; document.body.appendChild(textArea); textArea.focus(); textArea.select(); try { document.execCommand("copy"); alert("Results copied to clipboard!"); } catch (e) { alert("Failed to copy. Please copy manually."); } document.body.removeChild(textArea); }); } else { // Fallback for older browsers or non-secure contexts var textArea = document.createElement("textarea"); textArea.value = textToCopy; textArea.style.position = "fixed"; textArea.style.left = "-9999px"; document.body.appendChild(textArea); textArea.focus(); textArea.select(); try { document.execCommand("copy"); alert("Results copied to clipboard!"); } catch (e) { alert("Failed to copy. Please copy manually."); } document.body.removeChild(textArea); } } function updateChart(tdee, targetCals, weeksToGoal) { var ctx = calorieChart.getContext('2d'); // Destroy previous chart instance if it exists if (chartInstance) { chartInstance.destroy(); } // Calculate calorie levels for each week var labels = ['Start']; var tdeeData = [tdee]; var targetCalsData = [targetCals]; // Simulate calorie needs over time assuming linear weight loss // Approximate TDEE reduction due to weight loss: // For every ~7.7 kg lost, BMR decreases by about 100-150 kcal. TDEE is roughly 1.2-1.9 * BMR. // Let's approximate a TDEE decrease of ~15 kcal per kg lost. var tdeeDecreasePerKg = 15; // Estimated kcal reduction in TDEE per kg of weight loss var tdeeReductionFactor = 0.01; // Approximate reduction in TDEE per week as weight is lost var weeklyTdee = tdee; var weeklyTarget = targetCals; // More accurate simulation: decrease TDEE based on weight loss over time var numWeeks = Math.ceil(weeksToGoal); var weightLossPerWeek = parseFloat(lossRateInput.value); for (var i = 1; i <= numWeeks; i++) { var currentWeightLoss = i * weightLossPerWeek; var currentBmr = parseFloat(bmrResult.textContent) – (currentWeightLoss * 10); // Rough estimate var currentActivityMultiplier = parseFloat(activityLevelInput.dataset.multiplier || 1.375); // Get from element or default // Re-calculate activity multiplier based on selected value var activityMultiplierVal; switch (activityLevelInput.value) { case "sedentary": activityMultiplierVal = 1.2; break; case "lightlyActive": activityMultiplierVal = 1.375; break; case "moderatelyActive": activityMultiplierVal = 1.55; break; case "veryActive": activityMultiplierVal = 1.725; break; case "extraActive": activityMultiplierVal = 1.9; break; default: activityMultiplierVal = 1.2; } var currentTdee = Math.round(currentBmr * activityMultiplierVal); var currentTargetCals = currentTdee – (weightLossPerWeek * 7700 / 7); // Maintain deficit // Ensure target calories don't drop below a reasonable minimum if (currentTargetCals < 1200) currentTargetCals = 1200; if (currentTdee 0 && labels.length <= numWeeks) { labels.push("Week " + numWeeks); tdeeData.push(targetCalsData[targetCalsData.length -1]); // final target calories } chartInstance = new Chart(ctx, { type: 'line', data: { labels: labels, datasets: [{ label: 'Estimated TDEE (kcal/day)', data: tdeeData, borderColor: 'var(–primary-color)', backgroundColor: 'rgba(0, 74, 153, 0.2)', fill: false, tension: 0.1, pointRadius: 4, pointHoverRadius: 6, }, { label: 'Target Daily Intake (kcal/day)', data: targetCalsData, borderColor: 'var(–success-color)', backgroundColor: 'rgba(40, 167, 69, 0.2)', fill: false, tension: 0.1, pointRadius: 4, pointHoverRadius: 6, }] }, options: { responsive: true, maintainAspectRatio: false, scales: { y: { beginAtZero: false, title: { display: true, text: 'Calories (kcal/day)', color: '#555' } }, x: { title: { display: true, text: 'Time', color: '#555' } } }, plugins: { legend: { position: 'top', }, title: { display: true, text: 'Calorie Needs Over Weight Loss Journey', font: { size: 16 } } } } }); } // Function to toggle FAQ answers function toggleFaq(element) { var faqItem = element.closest('.faq-item'); faqItem.classList.toggle('open'); } // Initialize calculation on page load document.addEventListener("DOMContentLoaded", function() { calculateCalories(); // Add event listeners for real-time updates currentWeightInput.addEventListener("input", calculateCalories); heightInput.addEventListener("input", calculateCalories); ageInput.addEventListener("input", calculateCalories); genderInput.addEventListener("change", calculateCalories); activityLevelInput.addEventListener("change", calculateCalories); weightLossGoalInput.addEventListener("input", calculateCalories); lossRateInput.addEventListener("change", calculateCalories); });

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