Hi does the MM calculate the point of no return to automatically trigger the RTH, as for a Phantom 3?

No it does'nt

What exactly do you mean ? Such a point can only be roughly estimated especially due to the wind direction. The mini has a "Low Battery RTH mode". I think the variables for the calculation are the distance from the drone to the home point and the remaining charge of the battery. Lets say the drone is 1000m away, then the RTH is initiated if the battery has only 40%....for example.

It might have that actually, I saw that on one video, it just initiated RTH when battery was above 40%. I will look for the video.

Found the video, It seems MM does have that feature. It initiates RTH at 63% battery. See the video below (4:20).

Yet another example of how you'll get plenty of garbage answers to simple questions that can be answered by reading the manual.
This is from p13 of the Mavic Mini manual which you can find at:
https://dl.djicdn.com/downloads/ ... anual_v1.0_en_1.pdf

Low Battery RTH
Low  Battery  RTH  is  triggered  when  the  Intelligent  Flight  Battery  is  depleted  to  the  point  that  the  safe  return of the aircraft may be affected. Return home or land the aircraft immediately when prompted.
DJI Fly displays a warning when the battery level is low.
The aircraft will automatically return to the Home Point if no action is taken after a 10 second countdown.
The  user  can  cancel  RTH  by  pressing  the  RTH  button  on  the  remote  controller.  
If  RTH  is  cancelled  following  a  low  battery  level  warning,  the  Intelligent  Flight  Battery  may  not  have  enough  power  for  the  aircraft to land safely, which may lead to the aircraft crashing or being lost.
The aircraft will land automatically if the current battery level can only support the aircraft long enough to  descend  from  its  current  altitude.  
The user cannot cancel the auto landing but can use the remote controller to alter the aircraft’s direction during the landing process.

As it is always important to read the manual, thank you very much

Yes, reading the manual is always good, but remember not to ask in the forum anymore, but to ask Labroides in a PM, because all the other answers are bu****it.

Hi. Thank you for reaching out to DJI Forum and for the inquiry. With regards to this inquiry the DJI Mavic Mini doesn't automatically calculate the distance for it to trigger the RTH function for safe return of the said drone. It is recommended that once the low battery warning notification appears. It is best to return the drone home to prevent any incident or crash due to low battery situations. Thank you.