Working Time out for Ocean, is there a formula?

to work out the actual speed the ocean waves should have, for the render result to be the right speed.
Is there some kind of formula?

I have set a key frame in the Modifier Ocean where my animation should start. Frame 750 in this case Time is set to :1.00
On frame 933 I inserted the next key frame to stop the waves and set it on 20.00

How can I know the rendered speed result of the waves before I start rendering? :spin: