Atmosphere length in large planets?

[Breadbear83]

So there's this hypothetical feat of Frieza in dragon ball possibly being able to escape Namek explosion, which should mean crossing some point of the atmosphere

Thing is Namek is (within the wiki) over 600x the size of earth

So am I supposed to assume Namek has same atmosphere lengths as earth, or multiply the atmosphere lengths of earth by how bigger Namek is, or something else?

 

[Plants_vs_zombies_fan101]

U could do the first option as a Low ball then the second option as an highball

 

[Breadbear83]

Bump