Caloric need calculators use formulas which are derived from a statistical analysis of a population. If you take 100 women, who are all 32 years old, 5’4, and 120 pounds, and run 3 hours a week, and have the same desk job, the average of their caloric needs should be very close to the “answer” given by the formula. But what happens if you look at any one person?

Well, each individual is very different from the next. They will have different levels of muscle mass, different lifestyles, different basal metabolic rates, etc. And the difference in caloric needs between two people who on the surface appear very similar, could be quite large.

This means that it is foolhardy to use the caloric need calculator as some sort of holy grail of calorie counting for fat loss or muscle gain. Your true caloric needs will be determined only by trial and error by yourself. If you are eating above maintenance, you will gain weight. If you are eating below maintenance, you will lose weight. The best time to determine caloric needs is by trial and error during a period of time in which you are trying to maintain your weight.

Caloric need calculators provide a great starting point, BUT you will likely have to adjust based on your results.