You must be as bad a coffee drinker as me...............LOL
If you use the Food tracker diary, I found that you can track your amounts of coffee you have and how many calories you are taking in from drinking so many cups. I was shocked.
But hey, we love coffee.
there are a variety of phone/computer/web browser apps that can track things, particularly in the health section, if you have something with an 'app store'. 'optimism' is one, not sure if it's configurable enough for custom lists since it's been so long since i looked at it. plus they discontinued the free (partly disabled) version i think. there is probably something else. try different combinations of keywords when searching.
the first poster is right to a degree though. you cannot determine exact caffeine without using the same coffee and the same size cups at the same strength and keeping track. and you still wouldn't know the exact amount per cup, just relative to other days (without chemical analysis). tracking time for each dose is easier to do, and not the same thing per se.
Only drink coffee from your own pot and read the pot to see how many cups are left at the end of the day. If you make a second pot, you have to add the numbers together. Say you drank 4 cups from the first pot and 2 cups from the second. Six cups, although you may have fit them easily into 3 coffee mugs.