Calorie Deficit Calculator
Find out how long it will take to reach your goal weight based on your daily calorie deficit. See a full timeline and compare different deficit levels — conservative to aggressive.
Your weight loss plan 3,500 cal = 1 lb rule
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FAQs
How accurate is the 3,500 calories = 1 pound rule? ›
The 3,500 cal/lb rule is a useful approximation but not perfectly accurate. As you lose weight, your TDEE decreases (you're lighter, so you burn fewer calories), and your body adapts metabolically. Real-world weight loss typically slows after the first few weeks. A more accurate model (the NIH Body Weight Planner) accounts for this adaptation. For planning purposes, the 3,500 cal rule is a good starting point — expect to recalculate every 10–15 lbs lost.
What is the maximum safe calorie deficit? ›
Most health authorities recommend a maximum deficit of 500–1,000 calories per day, targeting 1–2 lbs of weight loss per week. Going below 1,200 calories/day (women) or 1,500 calories/day (men) risks nutritional deficiencies, muscle loss, and metabolic slowdown. Very low calorie diets (800 cal/day or less) should only be done under medical supervision. Slow, steady loss of 0.5–1% of body weight per week is generally best for long-term retention.