Depends on who you ask. Some say .7-.8 grams per KILOGRAM of bw. Others say as much as 2.5-3 grams per ibs of bw. I say it depends on what diet you use, how you train, your genetics and what drugs you are on andyour goals. Both extremes listed above are correct for some people. So... the real question becomes
1) what type of diet do you follow?
2) how do you train?
3) what drugs are you on?
4) what are your goals?
5) what are your current stats?
Without answering those, even giving you a ballpark figure would be quite silly, and rather pointless. Don't worry though, one of the next two or three people will say, "Get one gram per ibs of bw, and you'll be ok." Ahhh... such simplicity... to think how silly we are trying to be scientific when all we had to do was open a Wieder mag and get a nice simplistic answer.