Find out exactly how many calories to eat to reach your goal weight. Enter your stats, daily movement, training, target weight, and preferred deficit to get a daily calorie target, weekly loss rate, and estimated timeline.
A calorie deficit means eating fewer calories than your body burns each day. When you maintain a deficit consistently, your body uses stored energy (primarily body fat) to make up the difference. This is the fundamental mechanism behind all fat loss, regardless of diet type.
The size of your deficit determines how fast you lose weight. A 500 calorie daily deficit produces roughly 1 pound of fat loss per week. Larger deficits speed up weight loss but increase the risk of muscle loss, fatigue, and metabolic adaptation.
250 cal/day (0.5 lb/week)
Slow and steady
500 cal/day (1 lb/week)
Recommended
750 cal/day (1.5 lbs/week)
Moderate aggressive
1000 cal/day (2 lbs/week)
Aggressive
For most people, a 500 calorie daily deficit is the sweet spot. It produces meaningful fat loss (about 1 lb/week) while preserving muscle mass and energy levels. If you are significantly overweight, a 750-1000 cal deficit may be safe under guidance.
High deficit warning
Targets near 1,000 calories below TDEE are aggressive. Use them for short phases, keep protein high, maintain resistance training, and avoid going below minimum calories without medical guidance.
A safe deficit for most people is 500-750 calories per day, producing 1-1.5 lbs of weight loss per week. Going above 1000 cal/day deficit risks muscle loss, metabolic slowdown, and nutrient deficiencies. Women should generally not eat below 1200 calories/day and men below 1500 calories/day without medical supervision.
In theory, yes. One pound of fat contains roughly 3,500 calories, so a 500 cal/day deficit equals 3,500 per week, or about 1 pound. In practice, weight loss is not perfectly linear. Water retention, hormonal fluctuations, and metabolic adaptation cause weekly weight to vary. Track over 2-4 weeks to see the real trend.
Research suggests 0.5-1% of body weight per week is safe for muscle preservation. For a 180 lb person, that is 0.9-1.8 lbs per week. Key factors for preserving muscle: eat enough protein (1g per lb of body weight), continue resistance training, do not crash diet, and keep your deficit at 500-750 cal/day.
General guidelines suggest men should not go below 1,500 cal/day and women below 1,200 cal/day without medical supervision. This calculator enforces a 1,200 cal/day floor. If your calculated target is near these minimums, consider increasing activity instead of cutting calories further.
Yes, but it requires three things: (1) A moderate deficit (not extreme). (2) High protein intake, around 1g per pound of body weight. (3) Resistance training at least 3 times per week. Research shows trained individuals can maintain or even build muscle in a deficit when protein and training are sufficient.
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