How to calculate information rate?

Hi, Are you referring to inflation adjusted returns? You may go through below article : Five important formulas to calculate returns on investments

The article is about the investment. I want to know in general. Like we say due to inflation if you are keeping 1lakh as idle money and  not investing it anywhere the value of that money decreasing due to inflation. Same way Suppose if i have spent 1lakh in any party or to buy anything worth Rs 1lakh in the year 2000 So after 20years what is the value of 1lakh?. In other words how much more money I have to spend to buy the same thing in the year 2020    

Hi, Simple example : A liter of milk may costed us Rs 25 five years back, now costs Rs 50. So, we need to spend Rs 25 more to buy the same quantity of milk now. Related article : What is Inflation?