You want to lose weight. But you're not sure how many calories you should eat each day. Eating too much: Weight stays same or increases. Eating too little: You become exhausted and can't sustain it. You need to know your personal calorie target based on your body size, age, activity level, and goals. You could try to calculate this using complex formulas involving metabolic rate, activity multipliers, and goal adjustments. It would take significant time and require understanding multiple concepts. Or you could use a calorie calculator to instantly show you need 2,200 calories daily to maintain weight, 1,700 to lose weight, or 2,700 to gain weight. A calorie calculator estimates your daily calorie needs based on your personal characteristics (age, sex, weight, height, activity level) and goals (maintenance, weight loss, or weight gain). Calorie calculators are used by people managing weight, fitness enthusiasts tracking nutrition, athletes optimizing performance, healthcare prov...