Calorie Deficit Calculator

Yes. A 500-calorie daily deficit produces approximately 1 lb of fat loss per week (500 x 7 = 3,500 calories). This rate is widely considered safe and sustainable for most adults.

General guidelines suggest women should not go below 1,200 calories and men should not go below 1,500 calories per day without medical supervision. Going too low risks nutrient deficiencies and metabolic slowdown.

Calories are the primary driver, but factors like water retention, hormonal changes, sleep quality, stress, and medication can temporarily mask fat loss on the scale. Consistency over weeks is what matters.

One pound of body fat stores approximately 3,500 calories. This means a cumulative deficit of 3,500 calories, spread over any timeframe, will result in roughly one pound of fat loss.

Very large deficits (over 1,000 calories/day) can cause muscle loss, fatigue, nutrient deficiencies, and metabolic adaptation where your body slows its calorie burn. A moderate deficit of 500 to 750 calories/day is more effective long term.

Partially. If your deficit is already moderate (500 cal/day), eating back 50% to 75% of exercise calories helps prevent excessive hunger and muscle loss while still maintaining progress.

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