Ill copy and paste a post i made to another guy recently which may help you:
Im not a fan of the whole clean vs dirty bulk diet thing, what works for one may not work for the other. Meaning that if im eating maccas all day and your eating chicken breast, at the end of the week we both only made 100gram LBM gain. So we both gained pretty lean, just so happened to be that maccas gave me a lean bulk (and god willing some day it will lmao) and chicken breast worked for you. Hope that kinda makes sense because i just read it and confused myself hahaha.
To me a clean bulk is not necessarily what you eat but how your gains are. So a clean bulk for me is around 15% i think thats a good starting point, maybe less maybe a little more. basically once you work out your calorie intake increase it by 10-15% monitor your progress for a few weeks, then check, If weight has maintained the same, then increase the calories by 5-10%, If weight has increased maintain calories as they are.
A beginners true LBM gains are around the 200-300grams a week mark, less for experienced trainers.
Basically if your gaining more weight then 500grams a month there's a better chance that it is related to fat gains, but not always true! Dont confuse water weight with LBM, Training is another good indicator if your weights on lifts are going up chances are so are your lean gains..