A formula has been developed to help individuals determine how many calories someone needs to eat each day in order to start weight loss. This formula is: 655 plus (4.35 times weight in pounds) plus (4.7 times height in inches) and subtract (4.7 times age in years).
The number of calories a person should eat per day in order to lose weight depends on many factors. These include the person's current and goal weight, gender, height and age. The current activity level of the person will also play a role in how many calories are required. Of course, to lose weight a person will need to take in burn more calories than they consume.