# Watts and Joules on the RP3 software

Just for my understanding, I would like to know how the on-water time by RP3 could be calculated. It will be difficult to compare those scores which were trained on C2 and trained on RP3 by on-water time. However I imagine that if the on-water time would be calculated by the Watts, we could guesstimate the equivalent time through the Watts data.

For example, 7:00 on the 2k trial by C2 is equal to ave. 302watts. If it is possible to calculate the on-water time by the Watts, it would be very helpful.

A great question and one of the key answers which help coaches decide to switch form C2 to RP training.  You need to know

RP3 software – joules, watts, split

that the body of data you already have from athletes training on C2 is comparable to the data coming off the RP software.

Key points

1. RP3 Rowing App defaults to using C2 setting called “ergo” so your scores are comparable
2. RP3 software allows direct comparison to on-water times
3. RP3 software can use boat class and athlete weight and gives adjusted split, distance based on these calculated values

Here is the explanation about how the on water time is calculated for the Rowperfect software.    And the same information in a printable pdf  The Android software uses the same base as all the former versions of the software (Dos, Windows).

This was written by Casper Rekers who designed the Rowperfect and RP3 machines.  His calculation is based on athlete weight, the actual race time and the known mass of the boat and oars.

## Working with Watts on RP3 rowing machine

If you know the 500m split gold medal time for your boat class.
And you select Watts on the RP3 Rowing app software – you can display split and watts simultaneously so you can see the precise Watts needed for this split time.

This will tell you the watts (joules per second) or joules needed to achieve that on-water race time.
Here’s an article about Joules and athlete weight on RP which will help you understand the relationships between them.