How the inflation calculator works
The calculator multiplies your amount by the ratio of two Consumer Price Index values: value = amount × CPI at the end date ÷ CPI at the start date. For example, the CPI-U averaged 130.7 in 1990 and stood at 336.94 in September 2026, so $100 from 1990 is worth $257.80 in September 2026 dollars.
Choose a month for both dates for a month-to-month comparison, or leave the start month on Annual average to use the CPI for the whole year, which is the usual way to compare prices from a past year. The result also shows the cumulative change in prices and the average yearly inflation rate between the two dates.
It works in both directions. To find what today's money would have been worth in the past, swap the dates: $100 in September 2026 had the buying power of $38.79 in 1990.
Where the data comes from
All figures are the Consumer Price Index for All Urban Consumers (CPI-U), U.S. city average, all items, not seasonally adjusted, with 1982-84 = 100 (BLS series CUUR0000SA0), published monthly by the U.S. Bureau of Labor Statistics. It is the most widely used measure of US inflation and the index behind most "what is a dollar worth" calculations, including the BLS's own CPI inflation calculator.
The latest month included is September 2026 (CPI-U 336.94). BLS did not publish a CPI for October 2025 because of the 2025 lapse in federal appropriations, so that month cannot be selected; BLS calculated the 2025 annual average (321.943) from the other 11 months. We update the data file when BLS releases a new month.
How much has the dollar lost to inflation?
Prices are about 34 times higher than in 1913: $1 from 1913 buys what $34.03 buys in September 2026. More recently, $100 from 1970 is worth $868, $100 from 1980 is worth $409, $100 from 2000 is worth $196, and $100 from 2020 is worth $130.
Over the 12 months to September 2026, consumer prices rose 3.7% (CPI-U, not seasonally adjusted). That is the "headline" inflation rate reported in the news each month.
High inflation and deflation in US history
Inflation has varied widely. Annual average prices rose 13.5% in 1980, during the oil-price shocks of the late 1970s, and 8.0% in 2022 after the pandemic. Prices also fell in 13 years since 1913, mostly in the 1920s and during the Great Depression of the 1930s; the most recent was 2009, when the annual average CPI fell 0.4%.
Because inflation compounds, even moderate rates add up: at 3% a year, prices double in about 23 years.
US inflation by decade
Average yearly inflation by decade, from the annual average CPI-U (each decade measured from the last year of the decade before): 1920s -0.1%, 1930s -2.1%, 1940s 5.5%, 1950s 2.0%, 1960s 2.3%, 1970s 7.1%, 1980s 5.5%, 1990s 3.0%, 2000s 2.6%, 2010s 1.8%. The 1970s had the highest average inflation of any decade, while prices fell overall in the 1920s and the 1930s.
Each year has its own page with that year's monthly CPI, its inflation rate and examples in today's dollars, for example $1 in 1970, $1 in 1990 and $1 in 2000. The full list of years is below.
Annual averages versus single months
An annual average smooths out the ups and downs within a year, so it is the best choice when you know only the year of a price, such as an old salary or the price of a house. A single month is better when you know the exact date, for example to compare a rent from June 2021 with June 2026. Because CPI is not seasonally adjusted here, comparing the same month in two years avoids seasonal swings.
Using the calculator well
CPI-U measures the average price change for a basket of goods and services bought by urban consumers. Individual items can rise much faster or slower than the average: rents, medical care and college tuition have outpaced overall inflation for decades, while many electronics have become cheaper. Use the result as a guide to general buying power, not the price of a specific item.
Salaries are a common use: if you earned a salary in an earlier year, convert it to today's dollars to see whether your pay has kept up with prices. For future planning, remember that the CPI only covers the past; to estimate future costs, assume a rate such as 2% to 3% a year. For prices in India, use our India inflation calculator, which uses India's CPI.