Basal metabolic rate (BMR) is the amount of energy expended while at rest in a neutrally temperate environment, in the post-absorptive state (meaning that the digestive system is inactive, which requires about twelve hours of fasting in humans).

Formula based on Mifflin, ST St Jeor research in 1990 which is 5% more accurate than equation by Harris-Benedict equation in a survey in 2005. Also reference to Basal metabolic rate in Wikipedia
The BMR data is for referenc only to monitor your daily food intake. Other factors also influence the calory needs.

• Sedentary: Little or no exercise and desk job
• Lightly Active: Light exercise or sports 1-3 days a week
• Moderately Active: Moderate exercise or sports 3-5 days a week
• Very Active: Hard exercise or sports 6-7 days a week4
• Extremely Active: Hard daily exercise or sports and physical job