Answer:
It depends on how quickly the human in question puts one foot in front of the other -- factors such as length of stride, weight, and type of terrain effect this. Generally speaking, most people walk at 2.5 to 3 miles per hour. Typically 4 MPH is considered a brisk walk, and at about 6 MPH, you're jogging. Over a long distance (e.g., a marathon) 12 MPH is a world-record pace.