CPI Inflation Calculator

Convert a dollar amount from one period to another using CPI index values, and see the total inflation rate between the two dates.

Amount

CPI Value (Starting Period)

CPI Value (Ending Period)

Adjusting for inflation with CPI

The Consumer Price Index (CPI) tracks the average change in prices paid by consumers over time. Comparing CPI values from two different periods lets you convert an amount of money from one period into its equivalent purchasing power in another.

The formula

Equivalent Value = Amount × (CPI at End Period / CPI at Start Period). The percentage difference between the two CPI values gives the total inflation rate over that span.

This calculator is for general educational purposes. Use official CPI data (such as from a national statistics agency) for accurate index values, since figures vary by region and CPI series.

Last reviewed August 2026