Target Weight Loss Calculator

Losing approximately one pound of fat requires a total calorie deficit of about 3,500 calories. Enter your current weight, target weight, and the daily calorie deficit you plan to maintain to see how many days, weeks, and months it will take to reach your goal — along with your estimated weekly rate of loss. Use this calculator to set realistic expectations before starting a weight loss plan, evaluate whether your current deficit is producing progress fast enough, or compare different deficit levels to find the approach that best fits your timeline and lifestyle. A daily deficit of 500 calories creates roughly one pound of loss per week, while more aggressive deficits of 750–1,000 calories per day can accelerate the timeline but carry a higher risk of muscle loss and nutritional deficiencies. Most health professionals recommend staying within a 500–750 cal/day range for safe, sustainable fat loss. This calculator is a planning tool — real-world results vary due to metabolic adaptation, water retention, and changes in lean body mass over time.

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.