I have found this to be the most accurate triathlon predictor calc out there. It takes into account all the key information that others don’t. You input PR swim and run times and avg bike watts for a TT. On top of that you input the avg hours for your 2 biggest training weeks 6 weeks out from the event. You can ask it to predict IM or Half or probably oly too. I referenced it with a recent half iron I did and it was very accurate.
bump
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It actually seems to be pretty accurate. What’s interesting is how the times change for IM with relation to training volume (very sensitive).
I have no idea what my watts are 
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oh goodie, now all the lance fanatics have something to use to calculate his kona time.
Not even close. Many more variables are needed. Previous races (running, swimming, tri’s), history of training, years in sport, age, etc.
I put in my variables and I was 3 hours slower than any of my 10 Ironmans. I better up my mileage!!
My 20 minute bike watts are about 230 and it said I was going to have a 7 hour ride. I’m worried!
5K speed and Ironman speed are two different things.
Very low correlation of of variables to expected results.
I have no idea what my watts are
I reverse engineered my wattage based on known bike splits from several races… It says 280 but I have no idea what that means in terms of fitness…
way off for me too…
I have no idea about my watts either but used the 230 quoted on here
(I am a girl so no way that’s accurate)
and the bike split was the only split predicted to within 15min, swim off 1h, run off two hours (both predicted too slow)…for IM distance…
…
interesting, the olympic distance was predicted pretty well using the same variables…
Hi:
Please make sure you have entered the training volume inputs correctly. It sounds like you may have used the minimums by default. Also, it is difficult/impossible to predict a bike time without an accurate wattage with the way the calculator is currently set up. I appreciate your comments and would be interested to hear all of your inputs as well as your expected race time. As the creator, we’re always trying to improve. Thanks!
-Jesse
Perhaps it would be useful to set up a wattage ‘estimator’ using weight and race/training times over known distances. Neat calculator, thanks for the effort.
ken
The calculator predicted my sprint distance time from last weekend within 1 min!
However, it proved far less accurate at longer distances.
Hi:
We are considering setting up an option to input 20min TT pace in place of wattage. Thank you for your comments.
-Jesse
swim and run came out very close for me. I bike 5% faster than what the calculator estimated, but I have always thought my CT power numbers were on the low side based on my race times.
Suggestion: add a box for wetsuit or no and then subtract a few seconds per 100 if it’s yes. I would expect everyone to use a pool (non wetsuit) time for their swim input.
Agreed. However, the swim split time already assumes that the individual does their pool TT with no wetsuit and then races in open water with a suit. We have considered adding a button to accommodate both race options (suit and no suit) but decided to keep things simple since most people swim the pool with no suit but race open water with a suit. Thanks for the comments.
-Jesse
It was off on my IM time by about 3 hours, and off on my sprint by 10 minutes. Personal Disclaimer: I have been racing 25 years, so there is a lot of memory in those muscles.
Hi:
I’d be interested to hear what your inputs were as well as your expected output. Thanks for the comments!
-Jesse Kropelnicki
“the swim split time already assumes that the individual does their pool TT with no wetsuit and then races in open water with a suit”
Well, in that case, the swim split estimate was a couple of minutes high for me too. I was chalking the difference up to the wetsuit.
First of all this is really cool. Here are my observations from my inputs. My swim times are predicted much slower than I am. Maybe I dog it in the pool, or swim too hard in the race. I input 6 minutes with 6000 yds per week average training. It gives me a 1:20:00 IM, but I have doe 1:06:00 a couple of times. The bike was a bit slow,just a bit, and the run was pretty close. I guess I get a little more out of the training than this gives me credit for.
Like I said very cool though
That’s kinda cool.
I have no idea about wattage, so I used the 230 that other people have used.
It was about 5 minutes off of my overall time for olympic distance. None of the splits were off by more than a couple of minutes.
Of course, I’ve only done one road tri and I was sick a lot the month prior so I did not train at all. I would hope that I were much faster right now.