Estimate your daily calorie needs.
This is a general estimate for healthy adults. It is not medical advice and is not suitable for children, pregnancy or medical conditions. Do not eat below the minimum intake advised by your doctor, and speak to a professional before making big changes to your diet.
Your body burns calories even at rest. That is your basal metabolic rate, or BMR. This calculator estimates it with the Mifflin-St Jeor equation, which is widely used for healthy adults, then multiplies by an activity factor to estimate maintenance calories. Gentle targets of 250 or 500 calories above or below maintenance are shown, and goals that fall under common minimum intake levels are flagged. Real needs vary with body composition, genetics and health, so treat the result as a starting point.
Weigh yourself under similar conditions each week and judge progress over several weeks, not days. Focus on sustainable changes in food quality and activity instead of crash diets. Pregnant women, teenagers and people with medical conditions have different needs and should get personal advice.
It is an estimate and can be off by several hundred calories. Track your progress and adjust.
Eating very little can be unsafe. Large deficits should only be followed under medical supervision.