What is considered a safe weekly weight loss rate?
Losing 0.5% to 1.0% of your current total body weight per week is generally considered safe, sustainable, and muscle-sparing.
Weight Loss Calculator
Computes the required daily calorie deficit, weekly fat loss rate, and projected completion date to reach your target goal weight safely.
Scientific Formula & Exercise Physiology Standards
Equation: 3,500 kcal Rule Dynamic Energy Model | Peer-Reviewed Source: Wishnofsky Energy Equivalence Principle (adapted for metabolic maintenance)
Days to Goal = [Total Weight Loss (kg) × 7,700 kcal] ÷ Daily Calorie Deficit
Calculates the total energy deficit required and maps it across safe weekly loss rates of 0.25 kg (0.5 lb), 0.5 kg (1 lb), or 0.75 kg (1.5 lb) per week.
Step-by-Step Worked Example: Weight Loss Goal (85 kg down to 75 kg)
- Total loss required: 85 - 75 = 10 kg (22 lbs)
- Weeks needed: 10 kg ÷ 0.5 kg/wk = 20 weeks (140 days)
- Daily deficit: (0.5 × 7700) ÷ 7 = 550 kcal/day (Target: 1,950 kcal/day)
Calculation Result: Timeline: 20 weeks (Target daily intake: 1,950 kcal/day)
Clinical Nuances, Limitations & Best Practices
- Weight loss is rarely linear due to fluid shifts, hormonal fluctuations, and gradual metabolic adaptation.
Frequently Asked Questions (Weight Loss Calculator)
Related Health & Fitness Calculators
BMI Calculator
Calculate your Body Mass Index (BMI) and determine your healthy weight range.
Calculate →Ideal Weight Calculator
Compare ideal healthy body weights across Devine, Robinson, Miller, and Hamwi formulas.
Calculate →Calorie Calculator
Estimate your daily calorie needs for weight loss, maintenance, or muscle gain.
Calculate →Calorie Deficit Calculator
Calculate safe calorie deficits (10% to 25%) and weekly projected fat loss.
Calculate →