Half Ironman Swim Time Per Age Group

Swimming is by far my weakest discipline. Fortunately, it is also where the average triathletes lose the least amount of time. So let’s check that in more detail.

The average swim time across Half Ironman races is 40min 02s which translates to a pace of 2:06 min/100m. The women cover the 1.2 mi in 41min 20s (or 2:11 min/100m) and the men in 39min 38s (or 2:05 min/100m).

I found out that those times depend significantly on the Age Group and the specific course. So let’s check that in more detail.


  • I checked all Half Ironman races that happened in 2021 in North America, Europe and Oceania.
  • I excluded the ones which were shortened. The final database consists of 74,871 times from age-groupers and 807 from pros.
    A special thanks to obstri.com, which is gathering results of all Ironman and Half Ironman events. It made my life easier!


As you can see in the graph below, the average swim pace for the men is 2:05 min/100m. The highest pace is reached in the youngest age group (18-24) with 1:59 min/100m.

Even if the pace is drastically different between the first and the average age grouper, it is not that big in terms of duration. We are talking about “only” 13 min over the 1.2 mi.

It is a pretty similar situation for the women. They swim at an average pace of 2:11 min/100m, roughly 35s per 100m slower than the first triathletes. The fastest age group is also the youngest (18-24), with an average pace of 2:00 min/100m.


The graph below shows that something is going on in Oregon and Augusta (average pace of 1:23 min/100m and 1:32 min/100m, respectively).

The paces are significantly faster compared to the rest of the other 70.3. The reason is that those are down river swims. For me, those paces are currently only achievable in my dreams. Therefore, I can’t wait to give such a swim course a try 😉

Memphis was the slowest course with an average pace of 2:29 min/100m.

Same situation on the women’s side with Oregon (1:24 min/100m) and Augusta (1:36 min/100m), clearly leading the pack and Chattanooga being the slowest course with an average pace of 2:35 min/100m.

If you enjoyed this analysis, have a look at those two articles which cover the bike and run legs of Half Ironman races: