Running Pace Calculator The running pace calculator is a tool for runners that calculates pace, speed, time and splits for selected distance. Enter a distance and target time, pace or speed. The rest will be calculated for you. You can select a distance from a set of predefined standard race distances including 10k, 10 miles, 1/2 Marathon and Marathon, or enter your own (in meters, miles or kilometres). Distance for a split is determined based on pace. If pace is set in minutes per kilometre,