Target Weight Loss Calculator

One pound of body fat stores approximately 3,500 calories of energy. To estimate time to your goal, the calculator first finds the total calorie deficit needed: pounds to lose × 3,500. It then divides that total by your daily calorie deficit to get the number of days required. Days are converted to weeks (÷ 7) and months (÷ 30.44, the average calendar month length). Weekly loss rate is calculated as (daily deficit × 7) ÷ 3,500, showing how fast the scale should move each week. For example, a 500 cal/day deficit yields 3,500 calories per week, equating to roughly 1 lb per week. A 250 cal/day deficit produces about 0.5 lb per week — a slower but more sustainable approach. The 3,500 calorie rule is a well-established planning estimate, though real-world results vary due to metabolic adaptation and changes in body composition over time.