Question for the Inverse Square Law calcs.

[CNBA3]

I was trying to remember a crucial part of the Inverse Square Law calcs where you find the distance which a shockwave travels from the source of a Gravitational Binding Energy object like planets, do you calc the distances from the very center of the planet? or at the edge of it's surface?

Here are examples:

Serious Punch²

vsbattles.fandom.com

Death Star Power Output!

universeconquest.fandom.com

EDIT: Nevermind, I found what I was looking for, made a mistake, it can be closed or deleted. sorry.