Estimate your daily calorie needs in seconds. Enter your age, gender, height, and weight, then choose an activity level (or view BMR only) to see how many calories you need to maintain, lose, or gain weight. Works with US (ft/in, lb) and Metric (cm, kg) units. Ideal for men and women ages 2–120 who want quick, science-based calorie targets using the Mifflin–St Jeor equation.