1. Pace
  2. Age Grade
  3. Race Prediction
  4. Pete Pfitzinger Heart Rate Zones
  5. Race Splits
  6. Others’ Calculators


per kilometre

per mile


per hour

per second

Age Grade

Assigns a percentual value to a time you ran on a certain distance. Data via Alan Jones. This percent enables you to compare yourself to someone of a different age or gender. In essence this value is the ratio of your time to the world record (or expected world record) for someone in your category.

This does not mean that a value of 70% indicates you are in the top 30% of the world. The value is only there to compare with the values of other people.

years old

h m s


Race Prediction

This predicts your time in one race based on your time in a previous one. Formula devised by Pete Riegel in the 70s.


h m s


Pete Pfitzinger Heart Rate Zones

Using the numbers and categories in Faster Road Racing. Good book, go get it.

Zone Min Max
General aerobic
Lactate threshold

Race Splits

Given a race length, goal time, and split distance, give the split at every point.



Others’ Calculators