It doesn't take a rocket scientist

It doesn't take a rocket scientist (to do sth) also
You don't have to be a rocket scientist (to do sth)
It’s/sth is not rocket science

(This isn't all that advanced or hard to understand; it is easy to do or understand something; it is obvious)

большого ума не надо, чтобы...; не надо быть семи пядей во лбу, чтобы...; не надо иметь семь пядей во лбу, чтобы...; ежу понятно, что...; (это) не бином Ньютона

.....Cooking isn’t rocket science.
.....We often hear an easy task described by the phrase, “It isn’t rocket science!” However, teaching science for understanding is a demanding, high-level professional activity that requires much knowledge and many advanced skills. Teaching for science for understanding IS rocket science!
(perspective.pearsonaccess.com)
.....It doesn't take a rocket scientist to figure out that if you treat her well, she'll be happier. (CALD)
.....Drugs equals crime. It doesn't take a rocket scientist to figure that one out.(Cambridge Idioms Dictionary)

[it's a no-brainer]
[ежу понятно]