Consumer Price Index (CPI) Calculator to Calculate the Effects of Inflation Between Two Dates

CPI Inflation Calculator Sign

This free online between-two-dates inflation calculator will calculate what a past, present, or future sum of money was or will be worth at another point.

The calculator's historical inflation calculations are based on the actual United States Consumer Price Index, which ranges from 1913 to 2023 (updated annually).

Future inflation calculations are based on a combination of the CPI history and your estimated future inflation rate.

The calculator also calculates the average inflation rate for any past period, which will help to make more informed future rate predictions.

Finally, the Consumer Price Index Calculator also creates a printable, year-by-year report for each of your calculations.

NOTE: Your savings is losing its purchasing power much faster than the government would like you to believe. If you are tired of having your savings continually being devalued by government monetary policies, see The Biggest Aha! Moment of my Life video on my About Me page.

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CPI Inflation Calculator

Calculate the effects of inflation or deflation on a past, present, or future sum of money.

Special Instructions

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Selected Data Record:

A Data Record is a set of calculator entries that are stored in your web browser's Local Storage. If a Data Record is currently selected in the "Data" tab, this line will list the name you gave to that data record. If no data record is selected, or you have no entries stored for this calculator, the line will display "None".

DataData recordData recordSelected data record: None
Start amount:Start amount:Dollar amount for start year:Dollar amount for start year:

Dollar amount for start year:

Enter a dollar amount to begin calculating the effects of inflation or deflation on (without the dollar sign or any commas). This amount should coincide with the year you enter on the next line.

Start year:Start year:Start year:Start year:

Start year (4-digit #):

Enter the year that corresponds to the amount entered in the line above. Note that the start year can be a past, present, or future year, but cannot be earlier than 1913. To forecast the effects inflation will have on your present savings, enter the future year on this line.

End year:End year:End year:End year:

End year (4-digit #):

Enter the year you would like the calculations to stop at. Note that the CPI Calculator will only allow years from 1913 on up, and all calculations beyond 2023 will be forecasted based on your entry on the next line. To forecast the effects inflation will have on your present savings, enter the current year on this line.

Future rate:Future rate:Expected future average inflation rate:Expected future average inflation rate:

Expected future average inflation rate:

Enter the average annual rate of inflation you expect will occur for future years (without the percent sign). This figure will only be used if the time period involves any years beyond 2023. Note that non-government entities have estimated the average annual real rate of inflation is between 7% and 13%. At 7%, the purchasing power of your savings will decrease by roughly 50% every ten years.

End worth:End worth:Ending relative buying power:Ending relative buying power:

Ending relative buying power:

This amount is the ending relative buying power of the dollar amount entered after accounting for inflation from the start year to the end year. If the time period involves years later than 2023, a portion of this result is based on your future inflation rate entry.

Dollar chg:Dollar CPI change:Dollar change in CPI:Dollar change in CPI:

Dollar change in CPI:

This result represents the dollar amount difference between the starting buying power and the ending buying power. Note that a negative number indicates deflation, which is usually the result of the starting year being later than the ending year.

Percent chg:Percent CPI change:Percentage change in CPI:Percentage change in CPI:

Percentage change in CPI:

This is the total percentage the inflation rate increased or decreased from the start year to the end year.

Avg rate:Average rate:Average annual rate of inflation:Average annual rate of inflation:

Average annual rate of inflation:

This is the average annual rate of inflation from the start year to the end year.

If you would like to save the current entries to the secure online database, tap or click on the Data tab, select "New Data Record", give the data record a name, then tap or click the Save button. To save changes to previously saved entries, simply tap the Save button. Please select and "Clear" any data records you no longer need.

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Help and Tools


What CPI is, why it's important, and what causes it to rise or fall.

What is CPI?

CPI stands for Consumer Price Index, which is an index maintained and reported by the U.S. Bureau of Labor Statistics.

The Consumer Price Index is made up to two primary figures for each reporting period:

  • Index: The total average cost urban consumers pay for a predefined basket of goods and services.
  • Percent Change: The percentage the index changed from the last reporting period, which is often referred to as the rate of inflation (or deflation if the index shrinks).

For more information about the consumer price index, please visit the official CPI website.

Note: Non-government entities estimate the real inflation rate to be around 7% to 13% per year, which is far above what the CPI reports. In my opinion, this real rate of inflation enables the rich to get richer while the other 95% get poorer. After all, the other 95% don't have access to investments that yield higher returns than the real inflation rate. See what you can do about it in the The Biggest Aha! Moment of my Life video on my About Me page.

Why is the Inflation Rate Important?

Knowing the past rate of inflation is useful for predicting future inflation. And future predictions are most commonly used in the following ways:

  • Retirement Planning: In order to prepare for your retirement, you need to factor in inflation to predict how much you will need to earn in the future to afford your present lifestyle.
  • Adjusting Money Values: If you borrow or lend a sum of money today, the forecasted rate of inflation will help to determine what that sum will be worth when it is returned to the rightful owner.
  • Cost of Living Adjustments: In order for you to maintain your current standard of living, your annual salary or gross wages will need to keep pace with the annual rate of inflation (see the Salary Inflation Calculator to see what your raise needs to be this year).

In the case of retirement planning, if you determine you will need $50,000 (in today's dollars) in annual retirement income 20-years from now, and you estimate the average inflation rate will be 2.5%, the effects of inflation will mean you will need to earn $81,930.82 then in order to buy what $50,000 will buy today.

As for adjusting money values, if you were to lend me $1,000 today with the promise that I will pay you back in 10 years, and you anticipate a 2.5% inflation rate, when I pay you back, your buying power will have been reduced to $781.20. So to avoid losing buying power on the deal, you would need to insist that I pay you $1,280.08 at the end of the 10-year loan.

Finally, if you are not receiving annual cost of living raises equal to or greater than the rate of inflation, your buying power will decrease even if your wages are increasing.

What Causes the CPI to Rise or Fall?

While there are many factors that influence the CPI, the predominant factor is the state of the economy.

If the economy is shrinking, consumers have less money to spend, and therefore businesses are forced to reduce their prices to get rid of their excess supply of products. Widespread shrinking prices often cause the CPI to shrink (deflation), as was the case in 2009. If the federal reserve board determines the economy is shrinking too fast, it will lower interest rates to encourage new construction and innovation.

On the other hand, if the economy is growing, consumers have more money to spend. Therefore businesses tend to increase their prices to compensate for the increased demand (build new factories, hire more workers, etc.). Widespread price increases typically cause the CPI to rise (inflation). If the federal reserve board determines the economy is growing too fast, it will raise interest rates to discourage new construction and innovation.

Just a glance of the historical Consumer Price Index, and you will be able to quickly tell when the economy was shrinking (negative percent change) and growing the fastest (higher positive percent changes).

Adjust Calculator Width:

Move the slider to left and right to adjust the calculator width. Note that the Help and Tools panel will be hidden when the calculator is too wide to fit both on the screen. Moving the slider to the left will bring the instructions and tools panel back into view.

Also note that some calculators will reformat to accommodate the screen size as you make the calculator wider or narrower. If the calculator is narrow, columns of entry rows will be converted to a vertical entry form, whereas a wider calculator will display columns of entry rows, and the entry fields will be smaller in size ... since they will not need to be "thumb friendly".

Show/Hide Popup Keypads:

Select Show or Hide to show or hide the popup keypad icons located next to numeric entry fields. These are generally only needed for mobile devices that don't have decimal points in their numeric keypads. So if you are on a desktop, you may find the calculator to be more user-friendly and less cluttered without them.

Stick/Unstick Tools:

Select Stick or Unstick to stick or unstick the help and tools panel. Selecting "Stick" will keep the panel in view while scrolling the calculator vertically. If you find that annoying, select "Unstick" to keep the panel in a stationary position.

If the tools panel becomes "Unstuck" on its own, try clicking "Unstick" and then "Stick" to re-stick the panel.