About Caloric Needs Calculation
This calculator uses what is called the "Harris-Benedict Formula" to
determine your daily calorie needs. There are a few things that are
important to remember about this formula. First, the formula was
devised many years ago, and has in recent years been determined to
have up to a 20% error rate, depending upon the percentage of body fat
and other variables. (For this reason, the calculator shows plus and minus
5% and 20% so you can get an idea of the range.)
Secondly, the modification for your "lifestyle" (sedentary vs. moderately
active and so forth) is really a bit of a guess. "Sedentary" is "little or
no exercise" and you can imagine that there can be quite a bit of difference
between "little" and "no" exercise.
Weight loss cannot, unfortunately, be boiled down into an exact number.
All this can do is give you an idea of a potential range. Chances are good,
however, that if you limit your intake to the lower end of the spectrum,
you may be able to lose weight, but different people have different
metabolisms and so you may need fewer or more calories.
Calculation of your "Basal Metabolic Rate" (or "Resting Metabolic Rate" as it's
sometimes called) is only one tool in your fitness arsenal.