Technically, there is no magic number of calories we should all eat each day to lose weight. While most people can lose weight eating around 1,500 calories, you can assess your own personal caloric needs with a little math.
Why Estimate Your Caloric Needs?
To estimate how many calories you should consume in order to maintain your weight, you'll need to do a little math. By using a simple formula called the Harris-Benedict principle, you can assess your basal metabolic rate -- also known as your BMR.
(Then, to lose weight, you'll need to cut calories or burn extra calories and shoot for a level lower than the results you get with this formula.)
Calculate Your BMR
Your BMR is the amount of energy your body needs to function. We use about 60% of the calories we consume each day for basic bodily functions such as breathing.
Other factors that influence your BMR are height, weight, age and sex.
Step one is to calculate your BMR with the following formula:
655 + (4.3 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)
66 + (6.3 x weight in pounds) + (12.9 x height in inches) - (6.8 x age in years)
*(Please note that this formula applies only to adults.)
Step two: In order to incorporate activity into your daily caloric needs, do the following calculation:
•If you are sedentary : BMR x 20 percent
•If you are lightly active: BMR x 30 percent
•If you are moderately active (You exercise most days a week.): BMR x 40 percent
•If you are very active (You exercise intensely on a daily basis or for prolonged periods.): BMR x 50 percent
•If you are extra active (You do hard labor or are in athletic training.): BMR x 60 percent
Add this number to your BMR.
The result of this formula will be the number of calories you can eat every day and maintain your current weightt. In order to lose weight, you'll need to take in fewer calories than this result.
As you lose weight, you can re-calculate the formula to assess your new BMR.
To learn more about counting calories and search for the caloric content of many foods, as well as keep an online food diary, visit About.com's Calorie Count!
* source from http://www.about.com/
(Article posted are from sources available on the internet, My posting here is for easy references)