The BMR calculator helps you calculate your basal metabolic rate (BMR), the amount of energy your body burns while at rest in a neutrally temperate environment after 12 hours of eating no food.
This is basically the minimum number of calories your body needs to survive with no movement. For example, let's say (knock on wood) you were in a coma. No talking. No moving. Only breathing and pumping blood.
Your BMR is the minimum amount of energy (calories) needed to keep your vital organs functioning, such as your heart, brain, lungs nervous system, liver, kidneys, sex organs, skin and muscle. The older you are and the more muscle you lose, the lower your BMR.