SimWatts: How accurate is it?

Whilst not as accurate as a true power meter, SimWatts gives your a good reference point for your performance through a measurement that is direct result of your effort, rather than a reaction.

Every effort has been made to make SimWatts as accurate as possible, but it’s perfectly possible for the reading to vary from the output of a true power meter. This is because simple things can dramatically affect the resistance curve of your indoor trainer, such as ambient temperature, body weight and tyre pressure.