How many mgs of caffeine will it take for a 6 foot person to stay up and be awake for a good 3 or 4 hours?

Question

In this case it's an average weight male. Also, whats a good amount for waking up in the morning? Don't need a health lesson on caffeine, people, just an answer!

Answer 1

It depends from person to person - drink as much as you need.
I can drink coffee and fall asleep right away.
One cup has almost 200mg and its not advised to consume more than 600mg a day.

Answer 2

If you never drink coffee, a cup of coffee can keep you awake for 4 - 6 hours.

If you drink coffee every day, you'll need more cups of coffee for the same effect.