How US inflation is measured

This site uses the Consumer Price Index for All Urban Consumers (CPI-U), all items, U.S. city average, not seasonally adjusted, from the U.S. Bureau of Labor Statistics. It is the number most often used to compare dollars across time.

The index

The index is scaled to 100 for the years 1982 to 1984. In October 2026 it was 337.511, so prices were 3.38 times the 1982-84 level. In January 1913, the first month of the series, it was 9.8, so prices then were 9.8% of the 1982-84 level.

From index to dollars

To move an amount from one month to another multiply by the index of the later month and divide by the index of the earlier month. This is all the calculator does.

Yearly rates

For each year this site averages the 12 monthly indexes and compares with the average of the year before. A different method, December to December, gives slightly different yearly rates.

What it does not tell you

It is an average basket of urban consumers (not everyone in the United States) and includes many things that you may not buy.
It does not follow any one item: housing, medical care and education have risen at their own rates.
It is not seasonally adjusted here, so month-to-month changes include seasonal swings.

Common questions

What is the CPI-U?

The Consumer Price Index for All Urban Consumers: a measure published by the U.S. Bureau of Labor Statistics of the average change over time in prices paid by urban consumers for a basket of goods and services.

What does "1982-84 = 100" mean?

The index is scaled so that the average of 1982 to 1984 equals 100. An index of 337.511 means prices 3.38 times the 1982-84 level.

Sources

U.S. Bureau of Labor Statistics, Consumer Price Index for All Urban Consumers (CPI-U), U.S. city average, all items, not seasonally adjusted, index 1982-84 = 100 (series CUUR0000SA0), January 1913 to October 2026, read through the BLS public data API (bls.gov/cpi) on 13 November 2026.
BLS shows no value for October 2025 in the data, so that month is left out; yearly figures are the average of the 12 months and are shown only for 1913 to 2024.
Every result is index arithmetic: amount × (index in the later month ÷ index in the earlier month).

Data from the U.S. Bureau of Labor Statistics read on 13 November 2026; latest month October 2026. This site is independent and not connected with the BLS or any government. The CPI is an average of urban consumer prices and measures nothing about your own spending. Results are estimates, not financial advice.