The performance factors used to predict race times are based on work done by Pete Riegel, a research engineer and marathoner, in the
1980s. The factors are valid only for events which last no less than three and a half minutes and no more than 230 minutes.
Master runners tend to perform at slighter better than predicted times for longer distances as their shorter distance performances reflect
their loss of speed before endurance.
Select the distance raced and enter the time for that race; then select the distance for which you wish to know the predicted time.