Rookie numbers. You're going to have to pump those numbers up!
I actually weigh my coffee with a scale. I specifically drink Robusta coffee, since it has a higher caffeine content than Arabica.
Robusta has about 2.2-2.5% of caffeine. All of that caffeine isn't obviously going to get dissolved in normal coffee brewing, so only about 1.5% of the dry weight is going to get dissolved into the coffee as caffeine.
I drink precisely 80 grams (dry weighted) Robusta coffee each day, which comes to around 1200mg.
Being completely honest, I'm very addicted to the stuff and the only reason I don't die from that amount of caffeine is because I have been building my resistance to caffeine since I was 11 years old.