How does Watts saved or gained, equate to seconds saved in a Time Trial?

All other things being equal, how is watts saved by aero benefits or watts power increase from training, quantified in terms of seconds saved?

In other words for 10 mile (16 km) and 25 mile (40 km) time trials, how do are watts converted into potential time saved?

For example you hear things like “a tight skinsuit might save you 10 watts” or “I increased my FTP by 20 watts”.

How many seconds might this saving be over the distances I mentioned?


That depends on what your baseline is. You can play around with numbers here:
Keep in mind that your aerodynamics may differ from their assumptions, but it’ll give you a good ballpark.


Thanks for the link I will play around with the calculator.

I was also wondering if there is a general rule of thumb, like save 10 watts and you will should be 10 seconds quicker over 10 miles etc…

Can you elaborate?

Anyone with a rough idea?

Increase power by 10 watts and you should save about X seconds etc?

There’s no general estimate because of the number of variables. You need to fix the baseline power and the distance being traveled. Best to plug some numbers into the bike calculator linked above and compare.


It’s $60/year, but BestBikeSplit is THE tool for elite TTers and triathletes. Several variables you can adjust to answer all of your time savings questions. As someone who likes hilly routes, I use it to determine my Normalized Power required for a route to be completed in a fixed time OR for a given NP, how long will the course take me to complete.

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