Dear Aviraj, when there is an offer letter given, there are two categories that you see. CTC and Net Income. CTC is "Cost to the Company" which is a raw amount that the Company has chosen to spend on you including. Net Income is what you take home. And these are calculated per annum. And when you get a pay slip, it is shown as per month and for the month that you have worked. So, if it is a package that you ever hear, then it is Per Annum and not per month.