This is the app you need if you want to convert values in joules to calories, and also from calories to joules.
Go to the gym and make some sport and exercise and burn calories and calculate the value in joules.
The calorie is a unit of energy.
There are actually two units with that name that have been widely used. The small calorie or gram calorie (usually denoted cal) is the amount of heat energy needed to to raise the temperature of one gram of water by one degree Celsius (or one kelvin). The large calorie, food calorie, or kilocalorie (Cal or kcal) is the amount of heat needed to cause the same increase on one kilogram of water. Thus, 1 kcal = 1 Cal = 1000 cal.
