Will i burn more calories by running for 30 minutes than by walkin for 30 min ?

The difference between running 30 minutes and walking 30 minutes is not significant; the difference is that you can burn the same number of calories in a shorter amount of time running. Does that make sense? In other words if you walked 4 miles in one hour, you'd burn somewhere in the neighborhood of 500 calories (depending on age, , weight, lean muscle m, etc.). You could burn the same neighborhood of calories in just 36 minutes (instead of spending an hour of your time) by running the four miles at a nine-minute per mile pace.