Depends on a few factors such as as your bf%, age, training experience, goals, etc but if you want a simple answer that should cover most people it would be .8g/lb however take a look at the guide below for a more specific answer
Examine.com is a great website in general that is completely evidence based and compiles it’s info from all relevant research
https://examine.com/guides/protein-intake/
A systematic review by Morton identifies 1.6g/kg (.7g/lb) as the breakpoint where further increases no longer increase muscle hypertrophy. That paper recommended the upper half of the confidence interval to be safe, so 1.6-2.2g/kg or .7-1g/lb.
You can build muscle with less, but that is the range that optimizes muscle growth.
If you are looking to tune your diet it’s an aminos game. The 0.8 number is based on an average diet to hit 100% of the essential aminos but the amount you actually need will depend on what you’re eating, it’s amino content and bioavailability.
Unless you are a body builder or elite athlete it’s unlikely you need to focus excessively on it. FYI overall nutrition is also important, if you are deficient in any of the minerals used in muscle protein synthesis then it doesn’t matter if you have the right aminos or not.
Depends on a lot…for the Gen Pop folks….8 - 1.0g/lb of body weight unless you are extremely overweight, then use your goal weight as a guide. Always prioritize calories and protein if trying to lose weight.
It’s different for everyone, but I do think some people tend to underestimate the power of the human body. For example, it can be more difficult to build muscle on a cut, but for a beginner you can still blowup like a ballon on a minimal intake