Calories are the amount of energy in each food. Knowing the amount of Calories in our food can help us to balance the energy and weight of our body to be healthy. An average man needs around 2,500kcal (10,500kJ) a day. So, in order to stay fit and healthy you should keep your diet and perform regular excersises. The calories calculator given here is used to calculate the amount of calories burned while exercising based on your heart rate.