Calorie Deficit Calculator

A 500 kcal/day deficit is the standard recommendation for safe, sustainable weight loss of approximately 0.5 kg per week. Deficits over 1,000 kcal/day risk muscle loss, nutrient deficiency, and metabolic adaptation. Always ensure you are consuming at least 1,200 kcal/day (women) or 1,500 kcal/day (men).

As you lose weight, your BMR decreases because your body requires less energy to maintain a smaller mass. This is why the same deficit produces less weight loss over time. Recalculating your calorie needs every few kilograms helps keep your deficit accurate.

The 7,700 kcal/kg figure is a useful average but varies based on the ratio of fat to muscle lost. Water retention, hormonal changes, and metabolic adaptation also affect the scale, meaning real-world weight loss is rarely perfectly linear. The calculation is a guideline for planning, not a guarantee.