700 cals per lb muscle
3500 cals per lb fat
if the goal is one lb muscle a week, a 700 cal total surplus is needed over your maintenance(technically more since muscle building isnt chemically favorable)
so about 200-300cals over maintenance a day for 1lb of muscle a week(slow but ensures minute fat gain)
so if your maintenance is 2200-2300(eyetest) your bulk cal numbers would be 2400-2600
not that hard to eat that much
its when you eat way more than you need to that fat gains come in droves, anything that isnt made into muscle WILL become fat. and considering fat is extremely favorable to build in the body opposed to muscle, any "over" surplus i can ensure is going to fat
without eating well, you wont "bulk" on steroids either so i would be certain of what you want first