How much coffee do people use in their coffee maker?

I am trying to slowly phase out caffeine, so I am trying to control the amount of caffeinated coffee I use.

"The standard ratio for brewing coffee is 1-2 tablespoons of ground coffee per 6 ounces of water – 1 tablespoon for lighter coffee and 2 for stronger coffee. 

So how does that break down in your coffeemaker?

To fill a standard 12-cup coffeemaker, you will need 12-24 tablespoons (or between 3/4 and 1 1/2 cups) of ground coffee."

https://www.swiftrivercoffee.com/blog/2019/3/6/how-to-brew-the-perfect-pot-of-coffee

It is not clear if the tablespoons they are talking about are heaping tablespoons or level tablespoons.  A heaping tablespoon might be equal to 2 to 3 level tablespoons. 

The instructions on the cans of coffee I purchase say to use one heaping tablespoon for every 6 ounces of water.  That seems excessive to me.  That would be 10 heaping tablespoons for a pot of coffee.  

The way I make coffee is to use just enough to cover the bottom of the filter with coffee.  This means that it is heaping in the middle, less heaping toward the sides.  I measured this as 3 heaping tablespoons on my new coffee maker.  I might sometimes use 4.  This tastes fine to me and does not seem weak.

According to the Internet, a heaping tablespoon of Arabica coffee has 60 mg of caffeine.  Therefore three tablespoons would have 180 mg of caffeine for the entire pot.  By coincidence, this is the amount of caffeine in a large 20 once McDonald's coffee according to the internet.  So that would imply that Mcdonald's is using 3 times the amount of coffee that I am using.