Question

how much protein required in a day for muscle gain

Answer 1

1 gram of protein per pound of body weight (2.2 g/kg of BW) per day has been a bodybuilding rule of thumb for decades. Higher levels of protein intake, usually in the range of 1.2 – 1.5 grams per pound of body weight (2.6 – 3.3 g/kg BW) per day, are commonly recommended when “cutting” to lose fat.

Answer 2

one gram of protein must be needed daily for muscle gain.