To build mass your protein intake is based on your current lean body mass and should be 1-1.5gr/lb of it. Realistically if you find an accurate bmr and break down your fats calories carbs proteins and fiber (cal protein carb being most important) you'll find it a million times easier to build that mass.
Set up on a base macronutrient intake level (again based on your goals and bmr) and do it for 2 weeks with no cardio or only cardio on rest days (2-3wk) and weigh yourself nude after using the bathroom at the same time each morning, record that weight and after your beginning period of tracking those macros you can adjust as need be.
Set up on a base macronutrient intake level (again based on your goals and bmr) and do it for 2 weeks with no cardio or only cardio on rest days (2-3wk) and weigh yourself nude after using the bathroom at the same time each morning, record that weight and after your beginning period of tracking those macros you can adjust as need be.