How does extra hour pay is calculate at your work ?

How does extra hour pay is calculate at your work ? And do you think is it fair for your or profitable to org only? This is how it works at my work. Hour rate = CTC per month / 30 / 8 So if your CTC per month is 30K , the hour rate would be 30,000/30/8= 125/h Lol what i find unfair for employee in this is that HR count the 30days(working+holiday) and not only working days(~22)