This tool helps you predict the time of your next race based on a recent timed run.
How does it work?
To predict your timing (T2) for a race of distance D2, the following formula is used: T2 = T1 * ((D2/D1)^1.06) where T1 and D1 are the time and distance, respectively, of your timed run. This formula was proposed by Pete Riegel, and published in Runner’s World by Owen Anderson in 1997. It roughly says that a person’s speed declines by around 6% when the distance doubles.
– To get better estimates, use your timings for races which are similar to the ones you want to predict. For example, the estimate for a full marathon based on a half marathon timing will be more accurate than an estimate based on a 5km run.
– The time predictions are estimates of what a runner might achieve, if they train appropriately for the distance. It assumes that you have trained appropriately for the distance. Doing a 22-minute 5K today doesn’t mean you can do a sub-4h marathon tomorrow!
– The time predictions are based on average reduction of speed as the race distance increases, and this relationship will vary from person to person. The tool assumes you don’t have a natural significant bias towards either speed or endurance.