How this inflation calculator works
A dollar is not a fixed unit of value. The same dollar bought less in 2024 than in 2000, and far less than in 1980. To compare amounts across time, a salary from an old contract, the price of a house your parents bought, a pension promise, you need to convert them into the money of a single year. This calculator does that using the US Consumer Price Index.
At a glance
- Amounts are scaled by the ratio of annual average CPI-U between two years.
- Cumulative inflation and the compound average annual rate are both reported.
- Swap the years to deflate today's money back in time.
- The 2025 average uses eleven months; October 2025 was never published.
Enter an amount and two years. The calculator looks up the average CPI for each year, and scales the amount by the ratio between them. It also reports the total (cumulative) rise in prices, the compound average annual rate, and the reverse view: how much the original amount actually buys in the later year.
The formulas
Adjusted amount = Amount × CPI(to) ÷ CPI(from)
Cumulative inflation = CPI(to) ÷ CPI(from) − 1
Average annual rate = (CPI(to) ÷ CPI(from)) ^ (1 ÷ years) − 1
Purchasing power = Amount × CPI(from) ÷ CPI(to)
The average annual rate is a compound (geometric) figure, the single rate that, applied every year, would produce the same total change. It is a little lower than simply averaging each year's inflation rate, because compounding does part of the work.
Worked example: $100 from 2000 in 2024 money
CPI-U averaged 172.2 in 2000 and 313.7 in 2024.
Ratio: 313.689 ÷ 172.2 = 1.8217. Adjusted amount: 100 × 1.8217 = $182.17.
Cumulative inflation: 82.2% over 24 years. Average annual rate: 1.8217^(1/24) − 1 = 2.53% a year.
Worked example: the buying power of 2020 money
CPI-U averaged 258.8 in 2020 and 313.7 in 2024. You have $100 saved since 2020.
Purchasing power in 2024: 100 × 258.811 ÷ 313.689 = $82.51. Four years of unusually high inflation, 4.7%, 8.0%, 4.1% and 2.9%, removed about a sixth of the note's value.
What the CPI measures
The Consumer Price Index for All Urban Consumers (CPI-U) is compiled by the US Bureau of Labor Statistics from prices collected for a basket of goods and services, housing, food, transport, medical care, recreation and so on, weighted by what urban households actually spend. It is set to 100 for the 1982-84 period, so an index of 313.7 means prices were roughly 3.1 times their early-1980s level. This calculator uses the annual average of each year's twelve monthly readings, which smooths out seasonal swings and is the convention used by the BLS's own inflation calculator.
| Year | CPI-U annual average | $100 from that year in 2024 money |
|---|---|---|
| 1980 | 82.4 | $380.65 |
| 1990 | 130.7 | $240.08 |
| 2000 | 172.2 | $182.17 |
| 2010 | 218.1 | $143.86 |
| 2020 | 258.8 | $121.20 |
| 2024 | 313.7 | $100.00 |
The series here runs from 1913, the first year the BLS published, to the latest complete year. One caveat: the October 2025 reading was never published because of the federal government shutdown, so the 2025 annual average is the mean of eleven months. The effect on comparisons is well under a tenth of a percentage point.
Reading the year-by-year table
The table lists the CPI for every year in your range, the equivalent value of your amount in that year's money, and the inflation rate from the previous year. Scanning it shows how uneven inflation has been: near zero or negative in the early 1930s and 2009, above 13% in 1980, roughly 2% for most of the 2010s, then 8% in 2022. The chart plots the equivalent value, so a steep stretch means fast inflation.
Deflating instead of inflating
Swap the years and the calculator works backwards: how much would today's amount have been in an earlier year? This is useful for putting a modern salary or price into historical context, or for checking whether an old figure has "kept up". If a pension of $20,000 in 2000 is still $20,000 in 2024, deflating shows it now buys what about $11,000 did then.
What this calculator does not do
- Other countries. Only US CPI-U data is included; inflation in the UK, euro area or elsewhere differs and needs its own index.
- Specific goods. The CPI tracks a broad basket. House prices, college tuition and medical costs have risen faster than the index; electronics have fallen. For a particular item, look for its own price series.
- Regional differences. The index is a national average; living costs in individual cities move differently.
- Wages and returns. The calculator tells you what prices did, not what your savings or salary did. To see whether an investment beat inflation, compare its growth with the cumulative inflation shown here, or use the retirement calculator, which projects both together.
Using the result
Use the adjusted amount whenever you compare money across years, a fair like-for-like raise, the real cost of something bought long ago, or the real value of a fixed payment. Use the average annual rate as a planning assumption: the long-run US figure since 1913 is a little over 3% a year, and since 2000 about 2.5%. And use the purchasing-power figure as a reminder that cash left uninvested loses value every year even when the number on the statement does not change.