TP will often over estimate TSS for swim workouts, given they are often done at close to CSS pace and drills/fins/paddles will all play around with things.
My coach (who developed the initial concept of CSS for swimming) recommends we use around 60-70 TSS per hour for most swim sessions. I think he has a blog post in it, will see if I can find it.

Does it really make a difference.

If you know your distance you can roughly convert it to a Tss range and when you add up all the yards in the week it will basically shake out to an average of some kind anyway which won't be far off a median estimate and when you add that to bike and run it just falls into the noise because what you are not likely counting is Tss from life that can swing more wildly than your aggregate swim Tss swing in a week. So it likely makes zero diff in the big weekly picture.

No other responses yet as we are all googling TSS!

No science behind it, but I just input 2 TSS points for every 100m swum. Eg. a 2,000m swim =TSS 40

(This also works out to a TSS of 60-70 per hour, like the other poster suggested.)

Ps I also find this method is pretty consistent with the TSS scores calculated by Training peaks for my open water swims at similar efforts, so I'm happy its in the ballpark...

I just use this coach cox table in the link below. I use the average swim pace from the work out.

https://www.coachcox.co.uk/...scores-for-swimming/

Urbanchek method is the standard in swimming. I'm trying to find the T30 chart that gives your zones... (we would do a 2000m for time or 30 min for distance to get a baseline value).

https://myswimpro.com/...ming-training-zones/

---

___________________________________________
http://en.wikipedia.org/...eoesophageal_fistula
http://en.wikipedia.org/wiki/Cerebral_palsy
2020 National Masters Champion - M40-44 - 400m IM
Canadian Record Holder 35-39M & 40-44M - 200 m Butterfly (LCM)

I have worked on this on and off for a year. So lets get this out there: to have a semblance of an accurate calculation of TSS for swimming you have to use a chart, so you might as well use the gold standard.