Inflation Calculator (CPI)
Convert a dollar amount between years using official BLS CPI-U data, or project its future buying power at an assumed inflation rate.
Inflation is the rise in prices over time, which lowers what a dollar buys. This calculator uses official BLS Consumer Price Index (CPI-U) data to convert an amount from one year into another year's dollars, and shows the total and annual inflation over that span. It can also project an amount forward at an inflation rate you assume, which is a projection, not a forecast.
Assumptions
- Historical mode uses the U.S. Bureau of Labor Statistics CPI-U series (All Urban Consumers, U.S. city average, all items), annual averages, base 1982-84 = 100. The data covers 1913 through 2024 (the latest complete annual average; the 2025 average is pending). The adjusted value is the amount times the ratio of the two years' index values.
- The total inflation over the span is that index ratio minus one. The annualized rate is the compound annual rate implied by the ratio over the number of years, computed from the same data, so it reconciles exactly with the total.
- CPI is a broad national average across a fixed basket of goods and services. Your personal inflation can differ a lot depending on what you spend on, especially housing, healthcare, and education, which have risen faster than the overall index. CPI also does not capture quality changes or substitution perfectly.
- Projection mode is a PROJECTION, not a forecast. It grows the amount at the single annual rate you assume, compounded yearly, to show what the amount would need to become to keep its buying power, and what today's amount would be worth after that inflation. Past inflation does not predict future inflation, and actual future rates will differ.
- All figures are nominal dollars in the years stated, using calendar-year annual averages rather than specific months. This is an estimate for educational purposes only, not financial advice.
How it works
Inflation is the rise in the general price level over time, which lowers what a dollar buys. This calculator has two modes.
Historical mode uses the official Consumer Price Index. The Bureau of Labor Statistics publishes the CPI-U (Consumer Price Index for All Urban Consumers), an index of the average price of a basket of goods and services, with the 1982 to 1984 average set to 100. To express a past amount in a later year’s dollars, you multiply by the ratio of the two years’ index values:
adjusted = amount times CPI[to year] divided by CPI[from year]
The total inflation over the span is that ratio minus one. The annual rate is the compound annual rate implied by the ratio over the number of years, so it reconciles exactly with the total.
Projection mode is a projection, not a forecast. It grows an amount forward at a single inflation rate you assume, compounded each year, to show two things: how much you would need in the future to buy what the amount buys today, and what today’s amount would be worth after that much inflation.
Worked example
Historical: what is $100 from the year 2000 worth in 2024 dollars? The CPI-U annual average was 172.2 in 2000 and 313.689 in 2024.
- Adjusted value: $100 times 313.689 divided by 172.2 = $182.17.
- Total inflation over the span: 82.17 percent.
- Annual rate over those 24 years: about 2.53 percent.
Go further back and the effect compounds dramatically: $1 in 1913, the first year of the index, has the buying power of about $31.69 in 2024.
Projection: at an assumed 3 percent inflation for 10 years, $100 today would need to grow to about $134.39 to buy the same goods, and today’s $100 would be worth about $74.41 in buying power after that decade.
Data and limitations
The CPI-U data is BLS annual averages covering 1913 through 2024 (the latest complete annual average; the 2025 average is pending). CPI is a broad national average across a fixed basket. Your personal inflation can differ a lot depending on your spending, especially housing, healthcare, and education, which have risen faster than the overall index. The historical figures are real published data; the projection mode is a what-if at a rate you choose, and past inflation does not predict future inflation. This is an estimate for education, not financial advice.
Sources
Frequently asked questions
- How is inflation between two years calculated?
- With the Consumer Price Index. You divide the index value of the later year by the index value of the earlier year, and multiply the amount by that ratio. For example, if the index doubled between two years, a dollar from the earlier year has the buying power of two dollars in the later year.
- What is CPI-U?
- It is the Consumer Price Index for All Urban Consumers, the most widely used inflation measure in the United States, published monthly by the Bureau of Labor Statistics. It tracks the average price of a basket of goods and services for urban households. This calculator uses its annual averages.
- Does this predict future inflation?
- No. The historical mode uses real, published CPI data and does not forecast. The projection mode grows an amount at a rate you choose, which is a what-if, not a prediction. Past inflation does not reliably predict future inflation, so treat any projection as one scenario among many.
- Why does my personal inflation feel higher than CPI?
- Because CPI is a broad national average, and your spending mix is not the average. If a large share of your budget goes to categories that have risen faster than the overall index, such as housing, healthcare, or college, your personal inflation can run well above the headline CPI number.
Related calculators
Learn how this works
New to this topic? Our companion guide explains it in plain language: Inflation, Explained: What a Dollar Really Buys Over Time
Last reviewed June 2026.