A 2.5-mile, 30-minute run translates to approximately 244 calories burned for a person who weighs 125 pounds, according to Harvard Health Publications. If the runner weighs 155 or 185 pounds, the number of calories burned increases to 298 or 350 calories, respectively.
Of course, the amount of calories a person burns varies based on many factors. The more a person weighs, for example, the more calories she burns. This also applies to running speed and intensity. Running on tough terrains such as hills and trails burns more calories. On the flip side, slower runs on flat surfaces result in fewer calories burned.