Any goods which used daily in routine and the rise in their price level is termed as Inflation. This does measure the changes in the price range of commodities for a time interval along with other services offered. Inflation Rate Formula The other side of Inflation referred to as deflation which is the fall in the price index. The seller does use the basket to range the price index. They determine a value to the basket by analyzing the current value of it and then the value of basket determined based on the base period.