Calorie Calculator

Calories measure the energy supplied by food and used by the body. Even at complete rest, energy is required for breathing, circulation, temperature regulation, tissue repair, and nervous system activity. This baseline demand is called basal metabolic rate, or BMR. The calculator estimates BMR with the Mifflin-St Jeor equation, a widely used equation based on age, biological sex, body weight, and height. It is an estimate rather than a laboratory measurement, but it provides a practical starting point for nutrition planning. Daily life requires more energy than resting metabolism alone. Total daily energy expenditure, commonly called TDEE, adjusts BMR by an activity factor. Sedentary describes little structured exercise, while lightly active generally represents exercise one to three days per week. Moderate, very active, and extra active settings progressively account for more frequent training or physically demanding work. Choosing an honest average is more useful than choosing the most active day of a week. Wearable devices can provide context, although their calorie estimates also contain uncertainty. For weight maintenance, average calorie intake should roughly match TDEE over time. A weight-loss target is calculated with a moderate 500-calorie daily deficit, while gradual gain adds 300 calories. Actual weight change varies because water balance, food volume, training, sleep, medication, and metabolic adaptation all affect scale readings. The calculator applies a conservative minimum of 1,200 calories, but that floor is not a personalized medical recommendation. People with high energy needs may require substantially more food even while losing weight. Use the result as an initial target and monitor trends for at least two to four weeks. Weigh under consistent conditions, focus on a weekly average, and adjust intake in small increments if the trend differs from the goal. Food labels and serving estimates also introduce error, so consistency matters more than apparent precision. Protein, dietary fiber, fats, vitamins, minerals, and food quality remain important even when total calories are appropriate. Pregnancy, breastfeeding, adolescence, older age, eating disorders, metabolic disease, and intensive athletic training require additional care. A registered dietitian or clinician can account for health history and individual nutritional needs. This calculator is educational and does not diagnose a condition or replace professional advice.