Hello , I am a bit confused about how to calculate the sampling rate in the ADC :

In this tutorial :

https://www.avrfreaks.net/index.p...

The sampling rate was just the : Systemclk/prescalar

But on this topic :

https://www.avrfreaks.net/index.p...

Mike B calculated the sampling rate as Systemclk/noOfCyclesTakenForConversion

which equals SystemClk/13 in free running mode

So where is the right information?