How much excess protein to gain 1 pound of muscle?

Say that my body normally consumes about 50g of protein per day, just so I dont lose muscle. Over a period of time, how much protein excess should I consume to gain 1 pound of muscle? I mean, when you work out heavy does every gram of excess protein consumed over what your daily needs are, equate to 1 gram of gained muscle? If not, is there a mathmatical formula for getting the exact amount. I know people say "just eat 1g per pound of body weight and wait until you get the results you want in the mirror" So I guess the question is, if I work out 3x-5x per week and I consume 448 grams of excess protein over what I normally consume in 1 week, will that be 1 pound of muscle?