You want to understand how many calories your body burns just sitting still. Your body constantly burns calories even when sleeping. You need energy for breathing, heart beating, thinking, and all internal functions. But how much exactly? Without knowing this number, you can't accurately plan your diet or understand your weight management needs. You could use complex formulas involving your age, sex, weight, and height. It would take time and require remembering mathematical steps. Or you could use a BMR calculator to instantly show your basal metabolic rate is 1,450 calories per day—the amount you burn at complete rest. A BMR calculator computes your Basal Metabolic Rate by taking your personal characteristics (age, sex, weight, height) and calculating the calories your body burns at rest. BMR calculators are used by people managing weight, fitness professionals planning nutrition, healthcare providers counseling patients, athletes optimizing performance, and anyone wanting to und...