This program lets you calculate the correct window size by getting you to put 2 points that draw out the window.
Treat this more like a utility.

First, enter the width and height of the window you'd like to make where you want to find a good size. This is done so that every computer can run this program. Nonsensical inputs are overridden.
Then, just click around the blue window that was created. When you put 2 points, the yellow text at the bottom right will show you the window size of a window having such an area.
If you want to use this to get an accurate window size for a Tk object, you might find this useful. Otherwise, you most likely will not.

I heavily doubt anyone is interested in downloading this, but if you are, check out the Releases section.
I only have a Windows executable. If you have a Mac or Linux, you can only download it via the source code and running it with Python 3.10.