How many calories would I burn running 4 miles?

Depends on your speed mostly...if your goal is to lose weight than take the it at a light jog so your body will burn more fat. An average workout ( 1.5 miles at a 8 min/mile pace) burns around 300-350 calories on average. If you figured at that same pace you are probably looking for about 700-800 calories.

There's no set answer to this question. It really all depends on how quickly you run the distance. If you're banging out four minute miles then you're going to burn a lot more calories than if you took it at a leisurely jog.