Safe Weight Loss Rate Calculator

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Safe Weight Loss Rate Calculator

Calculate your daily calorie needs and a sustainable timeline to reach your target weight.

Male Female
Sedentary (Little to no exercise) Lightly Active (1-3 days/week) Moderately Active (3-5 days/week) Very Active (6-7 days/week) Extra Active (Physical job/Training)
0.25 kg per week (Slow & Steady) 0.5 kg per week (Recommended) 0.75 kg per week (Moderate) 1.0 kg per week (Aggressive but safe)

Your Personalized Results

Maintenance Calories (TDEE): 0 kcal
Daily Calorie Target for Loss: 0 kcal
Total Weight to Lose: 0 kg
Estimated Time to Goal: 0 weeks
⚠️ Warning: Your daily calorie target is very low. It is generally not recommended for women to go below 1,200 kcal or men below 1,500 kcal without medical supervision.

How to Use the Safe Weight Loss Rate Calculator

Achieving a healthy weight is not just about losing pounds quickly; it's about making sustainable lifestyle changes. This calculator uses the Mifflin-St Jeor Equation—widely considered the most accurate formula for estimating metabolic rate—to help you determine a realistic and safe timeline for your fitness journey.

What is a "Safe" Rate of Weight Loss?

Medical professionals and dietitians generally recommend losing 0.5 to 1 kilogram (1 to 2 pounds) per week. Losing weight at this rate ensures that you are primarily losing body fat rather than lean muscle mass or water weight. It also gives your skin time to adjust and helps prevent the "yo-yo" effect of rapid weight regain.

Understanding the Metrics

  • BMR (Basal Metabolic Rate): The number of calories your body needs to function at rest (breathing, circulating blood, cell production).
  • TDEE (Total Daily Energy Expenditure): The total calories you burn in a day, including physical activity. This is your "maintenance" level.
  • Caloric Deficit: To lose 0.5 kg of fat per week, you generally need a deficit of approximately 3,500 to 3,850 calories per week (about 500-550 calories per day).

Important Considerations

While the math of "calories in vs. calories out" is the foundation of weight loss, other factors play a role, including sleep quality, stress levels, and hormonal balance. Always prioritize nutrient-dense foods like lean proteins, vegetables, and whole grains to ensure your body receives proper fuel while in a deficit.

Note: If your target weight is significantly lower than your current weight, consult with a healthcare professional or registered dietitian to ensure your nutritional needs are met throughout your journey.

function calculateWeightLoss() { var gender = document.getElementById("swl_gender").value; var age = parseFloat(document.getElementById("swl_age").value); var weight = parseFloat(document.getElementById("swl_weight").value); var height = parseFloat(document.getElementById("swl_height").value); var activity = parseFloat(document.getElementById("swl_activity").value); var targetWeight = parseFloat(document.getElementById("swl_target").value); var weeklyRate = parseFloat(document.getElementById("swl_rate").value); if (isNaN(age) || isNaN(weight) || isNaN(height) || isNaN(targetWeight)) { alert("Please fill in all fields with valid numbers."); return; } if (targetWeight >= weight) { alert("Target weight must be lower than current weight for weight loss calculation."); return; } // BMR Calculation (Mifflin-St Jeor) var bmr; if (gender === "male") { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } // TDEE var tdee = bmr * activity; // Weight loss logic: ~7700 calories per kg var totalLossNeeded = weight – targetWeight; var dailyDeficit = (weeklyRate * 7700) / 7; var targetCalories = tdee – dailyDeficit; var weeksToGoal = totalLossNeeded / weeklyRate; // Results Display document.getElementById("res_tdee").innerHTML = Math.round(tdee) + " kcal"; document.getElementById("res_target_cal").innerHTML = Math.round(targetCalories) + " kcal"; document.getElementById("res_total_loss").innerHTML = totalLossNeeded.toFixed(1) + " kg"; document.getElementById("res_weeks").innerHTML = Math.ceil(weeksToGoal) + " weeks"; // Show Results Area document.getElementById("swl_results").style.display = "block"; // Safety Warning var warningEl = document.getElementById("swl_low_cal_warning"); if ((gender === "female" && targetCalories < 1200) || (gender === "male" && targetCalories < 1500)) { warningEl.style.display = "block"; } else { warningEl.style.display = "none"; } // Scroll to results document.getElementById("swl_results").scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }

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