Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic functions like breathing, circulation, and cell production while at complete rest.
Formula (Mifflin-St Jeor):
For men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (y) + 5
For women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (y) − 161