Basal Metabolic Rate, or BMR, is the number of calories your body needs to maintain basic physiological functions while at rest. This includes processes like breathing, circulation, and cell production. BMR is influenced by factors such as age, gender, weight, and muscle mass, with individuals who have more muscle generally requiring more calories. Understanding your BMR can help in managing weight and planning diets. By knowing how many calories your body needs at rest, you can better determine how many calories to consume or burn through exercise to achieve your health goals.