Tom's Inflation Calculator
Frequently Asked Questions


What happened to the Java version of Tom's Inflation Calculator?

What can Tom's Inflation Calculator do, and what can't it do?

Why won't the calculator run on my computer?

How can I use the calculator to convert wages and prices from past years into equivalent dollar amounts today?

How can I use the calculator to convert today's wages and prices into equivalent dollar amounts for past years?

How can I use the calculator to forecast future inflation?

What are the different data sets?

What does the "Show Inflation Data" button do?

What is the "cumulative inflation rate"?

Why don't the calculator's inflation rates match the rates I've seen elsewhere?

Why are the medical-cost inflation rates much lower than the rates I've seen elsewhere?

What is the source of data that the calculator uses?

What if I don't trust the government's official inflation data?

Why can't the calculator adjust inflation for different months during the same year?

Why doesn't the calculator include the starting year when making calculations?

How do different inflation rates affect the minimum-wage debate?

Which inflation index does the Federal Reserve use to guide its monetary policy?

Where can I send feedback about Tom's Inflation Calculator?  


What happened to the Java version of Tom's Inflation Calculator?

I decided to discontinue the Java version after 2016. The newer JavaScript version is now the only one. Functionally, they were almost identical. Technically, the older version was written in the Java programming language and the newer one is written in the JavaScript language. (Despite their similar names, they are very different programming languages.) To run the Java version, most web browsers required users to download and install Oracle's Java Runtime Environment (JRE) and customize their security settings. The JRE is free but is incompatible with some browsers, and some people prefer not to install it. Also, many people find it difficult to customize the security settings or worry about lowering their browser security.
The JavaScript version rarely requires a plug-in because almost all popular browsers support it as a standard feature. It also runs faster.

Apart from appearances, the main difference between the two versions is their data sets. Both versions default to the Consumer Price Index for All Urban Consumers (CPI-U, Annual Average). Both versions also offer the following alternative data sets: U.S. Medical-Cost Inflation (a CPI component), CPI-U (December to December instead of Annual Average), and ShadowStats (a private-sector source). In addition, the Java version had the Consumer Price Index (CPI) for Urban Wage Earners and Clerical Workers (CPI-W), and the JavaScript version has the Social Security Wage Index and the Personal Consumption Expenditures Price Index (PCEPI). If popular demand warrants it, I will add the CPI-W data to the JavaScript version in the future.

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What can Tom's Inflation Calculator do, and what can't it do?

Tom's Inflation Calculator converts U.S. dollars between two different years, adjusting the dollars for inflation (or deflation). Over time, wages and prices tend to rise, making direct comparisons between two years difficult. Past prices seem cheaper, but past wages were lower, too. Today's inflated dollars just don't buy as much stuff as past dollars did. Tom's Inflation Calculator adjusts for these differences, allowing you to make roughly equivalent comparisons of wages and prices between two years.

It's not an investment calculator. You can't use it to calculate how an investment will grow over time. However, you can use it as a companion with an investment calculator. First, use the investment calculator to estimate how large your savings will grow in the future. Then use the Inflation Calculator to estimate the actual purchasing power of that sum, as expressed in today's dollars. (See: How can I use the calculator to forecast future inflation?)

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Why won't the calculator run on my computer?

The JavaScript version is compatible with almost all web browsers without installing any plug-ins or changing any security settings. Exception: some browsers disable scripts for strict security reasons. Enabling JavaScript will allow my Inflation Calculator to run without compromising security. Some browsers let you specify which websites can run scripts and which cannot.

The original version of Tom's Inflation Calculator was a special type of computer program known as a Java applet. It required downloading and installing a special Java plug-in and customizing the browser's security settings. For various reasons, I decided to discontinue this version after 2016.

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How can I use the calculator to convert wages or prices from past years into equivalent dollar amounts today?

Type the wage or price from a past year into the Dollar Amount field. Type the year for that wage or price into the Starting Year field. Type the current year into the Target Year field. (Note: some data sets don't allow you to target the current year because the inflation data isn't available yet; the default data set uses a forecast for the current year.) Now click the Calculate button. The answer appears in the Converted Amount field.

For example, let's say you were making $25,000 a year in 2000. Have your wages kept pace with price inflation since then?

  • To find out, start with the default data set (U.S. Price Inflation, CPI-U, Annual Average):

  • Enter 25,000 in the Dollar Amount field.

  • Enter 2000 in the Starting Year field.

  • Enter 2017 in the Target Year field.

  • Click the Calculate button.

The answer—in this case, $35,524.30—appears in the Converted Amount field. If your current salary is less than that amount, you haven't kept up with general price inflation. Time for a raise!

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How can I use the calculator to convert today's wages and prices into equivalent dollar amounts for past years?

Type the wage or price from this year into the Dollar Amount field. Type this year into the Starting Year field. (Note: some data sets don't allow you to start with the current year because the inflation data isn't available yet; the default data set uses a forecast for the current year.) Type the past year to which you want to convert this wage or price into the Target Year field. Click the Calculate button. The answer appears in the Converted Amount field.

For example, suppose you just paid $2.50 for a gallon of regular gasoline. Somebody tells you that gasoline cost only 50 cents a gallon in 1975. But was gasoline really cheaper back then, after allowing for inflation?

  • To find out, use the default data set: U.S. Price Inflation (CPI-U, Annual Average). The currently selected data set is always indicated below the row of Inflation Calculator buttons. You can change it by clicking the Options button.

  • Enter 2.50 in the Dollar Amount field.

  • Enter 2017 in the Starting Year field.

  • Enter 1975 in the Target Year field.

  • Click on the Calculate button.

The answer—in this case, $0.54—appears in the Converted Amount field. So the $2.50 gasoline you bought in 2017 would be slightly more expensive (54 cents) than the 50-cent gasoline in 1975, after adjusting for inflation.

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How can I use the calculator to forecast future inflation?

Choose the default data set: Consumer Price Index (CPI-U, Annual Average). It's the only one with forecasts of inflation rates into the future. It's also the default data when the Inflation Calculator first runs. (The selection buttons indicate the active data set.)

You can use this data to estimate the effects of inflation as far forward as the year 2100. Of course, these forecasts are speculation. For the current year through 2026, the forecasts are from the Congressional Budget Office, a nonpartisan source. After that, the calculator automatically computes the mean average inflation rate since the U.S. government began gathering these statistics in 1913. In 2017, that average annual rate is 3.253%.

If you have used someone else's investment calculator to estimate how your savings will grow, you can enter those amounts into my Inflation Calculator to estimate the inflation-adjusted value of those future dollars. (My thanks to Penelope Reznor and Kodi Wolf for suggesting this feature.)

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What are the different data sets?

You can change the inflation data that the calculator uses for its arithmetic. You can also change the appearance of answers by turning dollar-and-cents formatting on or off. The default setting is on.

Use the selection buttons to choose from the six different data sets. When the calculator first runs, the default data set is "Consumer Price Index (CPI-U, 1665-2100)." Use this data to see how inflation is affecting the retail prices of goods and services. All data sets let you perform calculations forward or backward in time, for any years within the range of their data.

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