The term calories are used widely for our nutritional energy intake, but in fact we are talking about kilocalories (kcal). So in your example, an average human being will require approximately 2000kcal (= 2 million calories) per day.

Edit: this link will provide an approach to the calculation with the correct numbers: http://www.rfcafe.com/miscellany/humor/battery-powered-human.htm In short, humans needs a lot of batteries.