Streaming and Data Usage

Last month I got a notice I was close to the limit.  June 2025 spiked to 1.13TB!  ALL the months before were less than 200GB.   I assume it's because I was streaming a lot of the Live Eagle nest cameras.  Although in April (263GB)  I was watching the Live Great Moose Migration in Sweden for 3 weeks.  So now I check every day and keeping a log.  As of July 9, 8am I've used 38GB.  I'm trying to keep websites closed and sometimes shut down my iPhone and iPad.  I also have a Win 8.1 PC and a Win 11 Notebook.  So I was probably watching on both computers at the same time.

How do you calculate it?  How much does something use?  Besides time what else affects it?  Like quality ie: 720 or 1080 and  HD?  Or where you stream it from?   Oh, and in June I updated my Windows 10 to 11.  That was probably a big download.   

Does using the Xfinity Stream app to watch a live TV show count in the data usage?  What about Peacock I get through Xfinity?  I thought I read the Stream app doesn't count?                      

ps........How do I get to my first forum account?  I was listed as volvogirl.  But it's been a long time.  Did the forum change or drop it?  It wouldn't let me sign in with my current email, etc.