Let's see if I can explain this right (and, someone correct me if I'm wrong)...a kilocalorie is 1000 calories. For instance, a nutragrain bar has 130 kilocalories. Kilocalorie is equal to 1000 calories....so the bar would be 130kcal or 130,000 calories. The techincal term calorie means the amount of heat required to raise 1 gram of water 1 degree Celsius.
However, in lay man's terms...we say calorie instead of kilocalorie...which isn't exactly right, but, just think of all the people that would be tripping if they knew that when they are dieting on a 1300 calorie diet...they really mean a 1,300,000 calorie diet.
Is that clear as mud?