How Is Inflation Calculated?
Inflation is usually calculated by tracking the price changes in a basket of goods and services over time. In India, the Consumer Price Index (CPI) is commonly used for this purpose. The CPI measures the average price consumers pay for items like food, clothing, housing, and transportation. An increase in this index indicates rising prices—in other words, inflation.
Most everyday references to inflation revolve around consumer goods. But there are also other indices, like the Wholesale Price Index (WPI), which measures the cost of goods traded between corporations. While WPI is useful for economic insights, it’s the CPI that’s more relevant to your household budget.
Formula for Inflation
A general inflation calculation formula you’ll often see is:
Inflation Rate=(CPI_ current-CPI_ base)/ CPI_ base ×100%
Where:
- CPI_current is the Consumer Price Index in the current period
- CPI_base is the Consumer Price Index in the base period (an earlier reference year)
For example, if the CPI was 100 in 2015 (base year) and 120 in 2023, then:
Inflation Rate = Inflation Rate=(120-100)/100 × 100%=20%
In this scenario, it suggests that, on average, prices have risen by 20% since 2015. A reliable inflation rate calculator uses such formulas and available CPI data to crunch the numbers behind the scenes.