I am using Power Bi and searched and the forums and couldn't find anything similar to what I am using
So, I had a table that looks like this
I have used the following measures
RetentionRate = (ReturningUsers / PreviousDayDistinctUsers)*100%
ReturningUsers = DistinctUsers - NewUsers
PreviousDayDistinctUsers = CALCULATE(DISTINCTCOUNT(table[User], PREVIOUSDAY(table[Date])
NewUsers = CALCULATE(DISTINCTCOUNT(table[User] ), table[MonthlyNewUsers] = BLANK () )