Size of the delta of a branch from the parent


In the list of branchs we can see the size of each branch. But it doesn’t reflect the volume added by the branch, it shows the size of the database. If i understand correctly a new branch should not consume anything at first, it will grow only with the delta from the parent.
Is there a way to see the size of this delta ? And the size of the whole ?

Also it’s unfortunate to cannot create more projects, it was easier to test.

That said, branching is really an incredible things that open so much opportunity ! And it works !