Inflation Rate Calculator

LAST UPDATE: September 24th, 2020

Inflation rate calculator (via CPI)

Definition – What is the inflation rate?

The inflation rate is the rate that the consumer price index (CPI) is increasing. It is listed as a percentage.

As the price level of goods and services change over time, the CPI tracks the changes in prices.

A high inflation rate (considered to be more than 2%) means that prices are going up quickly, a low inflation rate (considered to be between 0 and 2%) means that prices are going up slowly. A negative inflation rate means that prices are going down.

Formula – How to calculate the inflation rate

Inflation Rate = ((Current Year’s CPI – Last Year’s CPI) ÷ Last Year’s CPI) x 100


If the current year’s CPI is 108 and last year’s CPI is 104, then:

Inflation Rate = (108 – 104) ÷ 104 = 4 ÷ 104 = 0.0385

Therefore, the inflation rate is 0.0385, or 3.85%

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