Fasting Calculator
Advanced Intermittent Fasting Calculator

⏰ Advanced Intermittent Fasting Calculator 🍃

Science-Based Fasting for Optimal Health & Weight Loss!

🔥 Fasting Streak: 0 days
16:8
Beginner Friendly
18:6
Intermediate
20:4
Advanced
OMAD
Expert Level
ADF
Alternate Day
5:2
Flexible

🎯 Your Personalized Fasting Plan

16:8
Recommended Method
0.5
kg/week Loss Rate
12
Weeks to Goal
300
Daily Calorie Deficit

📅 Your Daily Fasting Schedule

🧬 Expected Health Benefits

📊 Fasting Progress Tracker

Not Started

🕐 Eating Window: ${firstMeal} - ${lastMeal}

🚫 Fasting Period: ${lastMeal} - ${firstMeal} (next day)

`; }// Main calculation function function calculateFasting() { const currentWeight = parseFloat(document.getElementById('currentWeight').value); const targetWeight = parseFloat(document.getElementById('targetWeight').value); const height = parseFloat(document.getElementById('height').value); const age = parseFloat(document.getElementById('age').value); const gender = document.getElementById('gender').value; const activityLevel = document.getElementById('activityLevel').value; const goal = document.getElementById('fastingGoal').value; // Check if all required fields are filled if (!currentWeight || !targetWeight || !height || !age) { return; // Don't calculate if required fields are missing } // Calculate BMR and TDEE const bmr = calculateBMR(currentWeight, height, age, gender); const tdee = calculateTDEE(bmr, activityLevel); // Calculate weight loss parameters const weightToLose = currentWeight - targetWeight; const recommendedWeeklyLoss = Math.min(weightToLose * 0.1, 1); // Max 1kg per week const weeksToGoal = Math.ceil(weightToLose / recommendedWeeklyLoss); const dailyCalorieDeficit = recommendedWeeklyLoss * 7700 / 7; // 7700 cal per kg // Get method-specific benefits const benefits = getMethodBenefits(fastingData.selectedMethod, goal); // Update results document.getElementById('recommendedMethod').textContent = fastingData.selectedMethod; document.getElementById('weightLossRate').textContent = recommendedWeeklyLoss.toFixed(1); document.getElementById('targetDuration').textContent = weeksToGoal; document.getElementById('calorieDeficit').textContent = Math.round(dailyCalorieDeficit); // Update benefits updateBenefitsGrid(benefits); // Update timeline updateFastingSchedule(); // Show results document.getElementById('result').style.display = 'block'; }// Get benefits based on method and goal function getMethodBenefits(method, goal) { const benefitsData = { weight_loss: [ { title: "Fat Burning", desc: "Enhanced lipolysis during fasting periods" }, { title: "Insulin Sensitivity", desc: "Improved glucose metabolism" }, { title: "Metabolic Flexibility", desc: "Better fat oxidation capacity" } ], autophagy: [ { title: "Cellular Cleanup", desc: "Removal of damaged proteins and organelles" }, { title: "DNA Repair", desc: "Enhanced cellular repair mechanisms" }, { title: "Longevity Genes", desc: "Activation of SIRT1 and other longevity pathways" } ], metabolic_health: [ { title: "Blood Sugar Control", desc: "Stabilized glucose levels" }, { title: "Insulin Sensitivity", desc: "Reduced insulin resistance" }, { title: "Lipid Profile", desc: "Improved cholesterol ratios" } ], mental_clarity: [ { title: "BDNF Production", desc: "Increased brain-derived neurotrophic factor" }, { title: "Ketone Bodies", desc: "Alternative brain fuel for clarity" }, { title: "Neuroplasticity", desc: "Enhanced brain adaptability" } ] }; return benefitsData[goal] || benefitsData.weight_loss; }// Update benefits grid function updateBenefitsGrid(benefits) { const benefitsGrid = document.getElementById('benefitsGrid'); if (!benefitsGrid) return; benefitsGrid.innerHTML = benefits.map(benefit => `
${benefit.title}

${benefit.desc}

`).join(''); }// Timer functions function startFast() { fastingData.fastStartTime = new Date(); document.getElementById('startFastBtn').style.display = 'none'; document.getElementById('endFastBtn').style.display = 'inline-block'; // Start timer fastingData.fastTimer = setInterval(updateFastTimer, 1000); }function endFast() { if (fastingData.fastTimer) { clearInterval(fastingData.fastTimer); fastingData.fastTimer = null; } fastingData.fastStartTime = null; document.getElementById('startFastBtn').style.display = 'inline-block'; document.getElementById('endFastBtn').style.display = 'none'; document.getElementById('fastTimer').textContent = 'Not Started'; // Update streak (simple increment for demo) const currentStreak = parseInt(document.getElementById('fastingStreak').textContent); document.getElementById('fastingStreak').textContent = currentStreak + 1; }function updateFastTimer() { if (!fastingData.fastStartTime) return; const now = new Date(); const elapsed = now - fastingData.fastStartTime; const hours = Math.floor(elapsed / (1000 * 60 * 60)); const minutes = Math.floor((elapsed % (1000 * 60 * 60)) / (1000 * 60)); const seconds = Math.floor((elapsed % (1000 * 60)) / 1000); document.getElementById('fastTimer').textContent = `${hours.toString().padStart(2, '0')}:${minutes.toString().padStart(2, '0')}:${seconds.toString().padStart(2, '0')}`; }// Update recommendations based on goal function updateRecommendations() { const goal = document.getElementById('fastingGoal').value; const methodRecommendations = { weight_loss: '16:8', autophagy: '18:6', metabolic_health: '16:8', longevity: '20:4', muscle_gain: '16:8', mental_clarity: '18:6' }; const recommendedMethod = methodRecommendations[goal] || '16:8'; selectMethod(recommendedMethod); }// Initialize the calculator document.addEventListener('DOMContentLoaded', function() { // Set default method as selected selectMethod('16:8'); // Add sample values for testing document.getElementById('currentWeight').value = '80'; document.getElementById('targetWeight').value = '75'; document.getElementById('height').value = '175'; document.getElementById('age').value = '30'; // Auto-calculate with sample values setTimeout(() => { calculateFasting(); }, 500); });