Inflation Calculator
See how prices have changed between any two years, and what a past amount is worth in today's money. The calculator pulls live CPI-U figures straight from the U.S. Bureau of Labor Statistics.
Your inflation result will appear here
Pick a start and end year, enter an amount, then click calculate.
Quick Answer
Inflation between two years is (CPI_new - CPI_old) / CPI_old x 100. To restate a past amount in today's money, multiply it by (new index / old index). This tool uses live annual-average CPI-U data — U.S. city average, all items, not seasonally adjusted — from the Bureau of Labor Statistics.
How It Works: Formula & Variables
Inflation % = (CPI_new − CPI_old) / CPI_old × 100
Adjusted amount = Old amount × (Index_new / Index_old)
- CPI
- The Consumer Price Index for a given year — a measure of the average price level.
- Index ratio
- Dividing the newer index by the older one restates an amount in the newer year's dollars.
This calculator uses the CPI-U series (U.S. city average, all items, not seasonally adjusted) fetched live from the BLS. For a Europe or Belgium comparison, the equivalent measure is the Harmonised Index of Consumer Prices (HICP) published by Eurostat.
Sources: U.S. Bureau of Labor Statistics, CPI Q&A, BLS inflation calculator data, and U.S. Census Bureau, current vs. constant dollars.
Worked Examples
Example 1: inflation rate between two index values
If the CPI goes from 100.000 to 108.000, inflation is (108,000 − 100,000) / 100,000 × 100 = 8.0%.
Example 2: adjusting a dollar amount
Using illustrative index values from the U.S. Census Bureau, $1,000 in 1995 expressed in 2024 dollars is $1,000 × (174.4 / 90.9) = $1,000 × 1.9186 ≈ $1,918.60. The live calculator above does the same calculation with actual CPI-U figures.
Key Concepts
The index is a ratio, not a dollar figure: CPI values only mean something relative to the base period, so you compare them as ratios.
Nominal versus real: adjusting for inflation converts a nominal amount into constant purchasing power, which is what makes amounts from different years comparable.
Region matters: the US uses CPI-U, while Europe and Belgium use the HICP — different baskets and methods, so you can't mix them.
Common Mistakes
Confusing index points with percentages: a jump of 8 index points is only 8% if the starting index was 100.
Mixing seasonally adjusted and not-seasonally-adjusted data: the official calculator uses the not-seasonally-adjusted series, and switching between them introduces errors.
Using the wrong index for the region: CPI-U for the US, HICP for the EU and Belgium — they're not interchangeable.
Confusing nominal and real amounts: comparing a 1990s salary to a current one without adjusting for inflation overstates the difference.
Frequently Asked Questions
Inflation is a rise in the general level of prices. As prices climb, each dollar buys a little less, so the purchasing power of money falls over time.
The CPI-U — the Consumer Price Index for All Urban Consumers, U.S. city average, all items, not seasonally adjusted, published by the Bureau of Labor Statistics.
Take the newer CPI minus the older CPI, divide by the older CPI, and multiply by 100: (CPI_new - CPI_old) / CPI_old x 100.
Multiply the old amount by the ratio of the two index values: new index divided by old index.
It means prices are 10% higher than in the reference period, when the index was set to 100.
Index points only make sense relative to the base period's level, so they're hard to compare directly. Percentages put every comparison on the same footing.
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