Of course not - no calculator can account for all the glorious complexity that is the human body. Things like your muscle mass, genetics, health conditions, and hormones all play a role too. So use this as a general starting guideline, but be willing to adjust up or down based on your individual results and feelings of hunger/fullness. Don't let a number bully you!
t the end of the day, managing your body's nutrition is part math, part science experiment. The Harris-Benedict gives you a data-driven starting point to work from. But you're the boss! Use it as one tool in your overall journey towards feeling energized and healthy in your own skin.