I've always been told to use $1 from 1000 views as a guideline. This means that if your channel got 1 million views during 2019 you should have made about $1000 during last year. But it vary a lot depending on your channels niche, some niches pay a lot more than other. It also depends on your viewers location, ads can be a lot more expensive/cheaper depending on the nation they target.
I have actually kept statistics about this for my own channel from 2016 up to today and I have seen an pretty decent growth in how much money I get on averaged for 1000 views. It started with about $0.88/1000 views for 2016 and since it's steadily been increasing up to $1.36/1000 views for 2019. Also this far into 2020 show a big increase for January compared to January 2019. I'm in the gaming niche and most of my viewers are from the UK with the US in second place and Germany in third.
I'm not sure why this number is growing from year to year, do YouTube manage to get more many from the ads in 2020 compared to 2016? Has my niche evolved attracting more competition for the ads? Do less people use adblock? Do it effect that my channel has been grown getting a lot more views making my videos more attractive for ads? etc.