Below is a chart of swim paces for a variety of common triathlon distances. These are direct conversions not predictions. For example, the chart shows that if you were to swim 1:30 per 100 yards for an Ironman race you would finish in a time of 1 hour, 3 minutes and 22 seconds.
I suggest you use time trials throughout your training to help predict your race pace. Here are some TTs I use with my athletes based on their race distance:
- Sprint & Olympic/Intermediate Distance: 10x 100 yards, 10 seconds rest between intervals.
- Olympic/Intermediate, Half-Ironman: 3x 300 yards, 20 seconds rest between intervals.
- Ironman: 4x 500 yards, 30 seconds rest between intervals
After a short warm up perform the TT for your race distance. Then average out the work time and break down to 100 yard pace. Do not include rest time, this will make your race estimate slower than you are capable of.
Once you have the average 100 yard pace for the TT find it on the chart for an estimate of the time you could complete the swim leg in.
*Note that Ironman cut off time is 2 hours and 20 minutes.
For a list of distances for common triathlon races check out this posting.
Did you try the TTs? Let us know how it went. We are always eager to hear your comments!