# CSS Calculation **URL:** \ **Category:** General\ **Created:** [January 23, 2024, 4:11pm UTC](https://forum.athletica.ai/t/css-calculation/1121 "2024-01-23T16:11:36Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Muta](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/m/7cd45c/32.png) [@Muta](https://forum.athletica.ai/u/Muta)\ **Post date:** [January 23, 2024, 4:11pm UTC](https://forum.athletica.ai/t/css-calculation/1121/1 "2024-01-23T16:11:36Z")
Wondering how I calculate my CSS from the 400 and 50 times. Thanks ---
**Author:** ![Prof](https://forum.athletica.ai/user_avatar/forum.athletica.ai/prof/32/28_2.png) [@Prof](https://forum.athletica.ai/u/Prof)\ **Post date:** [January 23, 2024, 4:40pm UTC](https://forum.athletica.ai/t/css-calculation/1121/2 "2024-01-23T16:40:09Z")
Hi @Muta. Please send me your times via DM and I’ll calculate and update for you. The ability to calculate and update is in development. As well, we can’t yet automate this threshold determination like we do with running and cycling because the swim pace measurement on the watches isn’t precise enough yet, so we still need to do old fashion stopwatch work for now to test for accuracy and zone calibrations. Best, Paul ---
**Author:** ![Muta](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/m/7cd45c/32.png) [@Muta](https://forum.athletica.ai/u/Muta)\ **Post date:** [January 23, 2024, 5:31pm UTC](https://forum.athletica.ai/t/css-calculation/1121/3 "2024-01-23T17:31:31Z")
400 yds in 5:27 and the 50 yds in :33 ---
**Author:** ![Prof](https://forum.athletica.ai/user_avatar/forum.athletica.ai/prof/32/28_2.png) [@Prof](https://forum.athletica.ai/u/Prof)\ **Post date:** [January 23, 2024, 5:36pm UTC](https://forum.athletica.ai/t/css-calculation/1121/4 "2024-01-23T17:36:59Z")
You’re quick! 1:24 and can see it was already set that way in your threshold settings. ---
**Author:** ![Muta](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/m/7cd45c/32.png) [@Muta](https://forum.athletica.ai/u/Muta)\ **Post date:** [January 23, 2024, 11:44pm UTC](https://forum.athletica.ai/t/css-calculation/1121/5 "2024-01-23T23:44:00Z")
Thanks I want to be quicker. I’m in the free trial right now but I’m going to sign up and give it a crack. Thanks for your help ---
**Author:** ![Swimfast](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/s/90ced4/32.png) [@Swimfast](https://forum.athletica.ai/u/Swimfast)\ **Post date:** [March 4, 2024, 5:15am UTC](https://forum.athletica.ai/t/css-calculation/1121/6 "2024-03-04T05:15:44Z")
Can my CSS be calculated please as well and entered. Will this change my swim zones I did the css test workout today 400 m 6:07 50m 37.0 Thanks ---
**Author:** ![Marjaana](https://forum.athletica.ai/user_avatar/forum.athletica.ai/marjaana/32/4122_2.png) [@Marjaana](https://forum.athletica.ai/u/Marjaana)\ **Post date:** [March 4, 2024, 12:39pm UTC](https://forum.athletica.ai/t/css-calculation/1121/7 "2024-03-04T12:39:26Z")
Hey @Swimfast Based on your test times, your css is 1:46 min/100m. I have updated your swim threshold and yes, your swim zones will changes accordingly. In the future you can insert new thresholds on your settings - training - thresholds 🙏😄 Happy training, Marjaana ---
**Author:** ![Swimfast](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/s/90ced4/32.png) [@Swimfast](https://forum.athletica.ai/u/Swimfast)\ **Post date:** [March 4, 2024, 8:57pm UTC](https://forum.athletica.ai/t/css-calculation/1121/8 "2024-03-04T20:57:48Z")
Thanks very much Marjaana! ---
**Author:** ![Marjaana](https://forum.athletica.ai/user_avatar/forum.athletica.ai/marjaana/32/4122_2.png) [@Marjaana](https://forum.athletica.ai/u/Marjaana)\ **Post date:** [March 5, 2024, 12:45pm UTC](https://forum.athletica.ai/t/css-calculation/1121/9 "2024-03-05T12:45:04Z")
You welcome, @Swimfast - love your handle ❤ Keep swimming fast! ---
**Author:** ![Wombat](https://forum.athletica.ai/user_avatar/forum.athletica.ai/wombat/32/2037_2.png) [@Wombat](https://forum.athletica.ai/u/Wombat)\ **Post date:** [February 16, 2025, 11:25pm UTC](https://forum.athletica.ai/t/css-calculation/1121/10 "2025-02-16T23:25:41Z")
Wanting to check my CSS calculation after the CSS test this morning - I think the program has missed the critical laps. In the 1500m sett I sawm 7:40.4 for the 400m and 45secs for the 50m. Using the calculations on the athletica website (D1-D2/T1-T2) I get a CSS of 1:58/100. The AI prompted me to update my thresholds to 2:24 after the test. When I log in however it still has my old CSS of 2:10. Is that correct? Thanks ---
**Author:** ![Prof](https://forum.athletica.ai/user_avatar/forum.athletica.ai/prof/32/28_2.png) [@Prof](https://forum.athletica.ai/u/Prof)\ **Post date:** [February 17, 2025, 2:56am UTC](https://forum.athletica.ai/t/css-calculation/1121/11 "2025-02-17T02:56:04Z")
Hi @Wombat … there are still some issues with the swimming sync for thresholds so I have adjusted your threshold manually in your zone settings (Overview). ---
**Author:** ![kuLa](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/k/b487fb/32.png) [@kuLa](https://forum.athletica.ai/u/kuLa)\ **Post date:** [June 21, 2026, 6:13pm UTC](https://forum.athletica.ai/t/css-calculation/1121/12 "2026-06-21T18:13:29Z")
Looks like there are still some issues as I have swam CSS test over 72h ago and still can’t see any adjustment to my swim zones and my profile. It also looks like my best efforts hasn’t been noted by the system either. Is there a possibility that somebody from Athletica team (@Prof) could have a look at the backends what went wrong? I’m interested how my swim threshold HR looks like more than anything else as I calculated my pace zones manualy. ---
**Author:** ![kimberg](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/k/5fc32e/32.png) [@kimberg](https://forum.athletica.ai/u/kimberg)\ **Post date:** [July 7, 2026, 4:59pm UTC](https://forum.athletica.ai/t/css-calculation/1121/13 "2026-07-07T16:59:03Z")
What are were your 400 and 50 times? ---
**Author:** ![kuLa](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/k/b487fb/32.png) [@kuLa](https://forum.athletica.ai/u/kuLa)\ **Post date:** [July 7, 2026, 6:48pm UTC](https://forum.athletica.ai/t/css-calculation/1121/14 "2026-07-07T18:48:15Z")
I’m not sure how the raw time numbers may help in establishing HR based threshold but here they are: 400 - 5:35:40 50 - 0:31:20 ---
**Author:** ![kimberg](https://forum.athletica.ai/letter_avatar_proxy/v4/letter/k/5fc32e/32.png) [@kimberg](https://forum.athletica.ai/u/kimberg)\ **Post date:** [July 7, 2026, 8:15pm UTC](https://forum.athletica.ai/t/css-calculation/1121/15 "2026-07-07T20:15:01Z")
Ah, apologies, I missed the HR section in there. Yes those numbers only correlate to pace. Personally I don’t swim by HR, it takes almost a full lap for the HR to shift at all, but first make sure that you have “ask me” turned on for zone updates so you can see if/when it changes. And if no changes, then ping support@athletica.ai to see about the HR zones.