How to get use of the whole usable Screenheight

Question

Hello community :)
Which is the best way to get use of the whole usable screenheight? If i use:
window.screen.availHeight;
in Javascript it gets the screenheight, but this ignores the used space for the topbar in the output, so the webapp becomes scrollable.

Answer 1

use

window.outerHeight;

or

this.outerHeight;

Answer 2

Thank you kayla X ren :)
window.innerHeight worked fine.
I used it in my code "flipball" but until now my objects moved out of the screen.

Should i edit my question to make the problem more understandable?