Let's say I know how much caffeine I drank and when. Just knowing my sex, weight (and maybe height), what is the best estimate for how much caffeine is in my system now?
For example: Suppose I drank 180 mg of caffeine 5 hours ago, another 180 mg of caffeine 2 hours ago, I'm female and weigh 140 pounds.
I'm guessing food intake may also have a lot to do with it, but let's ignore that. Is a good estimate available?
Motivation: I am logging my blood pressure and want to know if it's correlated with the amount of caffeine in my blood. Rather than just write down how much caffeine I had that day, I wondered if there might be a better measure of how much caffeine I have at the time of measurement.