Bulking is one of the most reliable methods that lifters can use for packing on muscle mass. When considering how to bulk up properly, it's important to recognize the bigger picture.

What is bulking? Put simply, it’s taking in more calories that you need per day, so that—with the right training program, of course—those excess calories go to build muscle.

How to Bulk Up?

When approaching a bulking phase, you first need to consider how much muscle mass you want to gain, how much time you have to do it, and what ratio of muscle-to-fat gain is acceptable to you. After figuring out how many calories someone can eat per day without gaining or losing (tracking your calorie intake for a week and then taking an average is one easy way to do it), bumping up daily calories by 250 to 500 each week, depending on how aggressive the bulker wants to be.



Sources - https://www.menshealth.com/fitness/a26114988/how-to-bulk/