Exactly how many calories do you burn running is a puzzling query. There are many obvious factors to take into consideration if you really want to calculate the calories you burn running. Sure there is the "how fat", "how far", and "how hard" queries to bring into question, but we'll bet there are some other factors you never thought of. Running varies by many things, so let's find out just what determines your caloric loss!
First off, running burns about 50% more calories than walking over the same distance. That's just an average, but depending on your average speed while running, its possible to burn up to four times as many calories as compared to walking. Even at slower jogging speeds your body has to balance its center of gravity through the push given by your legs, which is very tiring after awhile.
There is a simple formula to determine the amount of calories you burn running. Granted, it's not always the most accurate predictor of weight loss, but hey, it can give you a general idea of those calories you are burning off while running. The formula goes like this: BW x 0.63 = RC/M. "BW" stands for your own body weight in pounds while "RC/M" stands for the amount of Calories burnt while running per mile. For example, a 160 pound person would burn 100.8 Calories while running a mile.
However, there are other factors to consider. The above, simplistic formula assumes you are running in normal weather. Heat can cause more sweating, put more pressure on your body, and force your organs to work harder just to keep you moving. Running faster, and even sprinting can shave off more from your oh-so-high caloric intake than predicted. Good luck, and run smart!