In economics, the inflation rate is the rate of increase of the average price level (a measure of inflation). If one likes analogies, the size of a balloon is like the price level, while the inflation rate is how quickly it grows in size. Alternatively, the inflation rate is the rate of decrease in the purchasing power of money. Buyers bargain for good prices while sellers put forth their best front in Chichicastenango Market, Guatemala. ... In economics, purchasing power refers to the amount of goods and services a given amount of money -- or, more generally, liquid assets -- can buy. ...
If P1 is the current average price level and P0 is the price level a year ago, the rate of inflation during the year might be measured as follows:
inflation rate = (P1 - P0)/P0, stated as a percentage (x 100).
There are other ways of calculating the inflation rate, such as the natural log of P1minus the natural log of P0, again stated as a The natural logarithm is the logarithm to the base e, where e is approximately equal to 2. ...