How do levels work when transferring Pokemon from go to lets go?

Question

I think its self-explanatory

Answer 1

It depends on the power-up level of the GO mon in question. (Check it with the curved white bar at the top of the summary) depending on how full that bar is, a level will be assigned. 1 is the minimum, while 40 is the maximum.

Source: https://bulbapedia.bulbagarden.net/wiki/GO_Park