Inflation Calculator
A dollar is not a unit of measurement - it is a share of a shifting basket. $100 in 1990 has the buying power of roughly $240 today; $100 in 1920 had the power of about $1,600. This calculator runs those conversions on the Bureau of Labor Statistics' CPI-U annual averages, from 1913 to the present, and shows not just the headline number but the machinery behind it: cumulative inflation and the compound average rate per year.
That yearly rate is the number worth internalizing: even the 'quiet' 2-3% years halve a dollar's value in 25-35 years, which is why a savings account under inflation is a slow leak with good manners. The note under the result keeps the map honest - CPI tracks an average basket, and your personal basket (housing, health, tuition) has its own weather.
How to use
- Enter an amount and the year it came from.
- Enter the year to convert to - today's money is the usual target.
- Read the converted value, cumulative inflation and average annual rate.
Frequently asked questions
How is inflation calculated between two years?
By the Consumer Price Index: value × (CPI of the later year ÷ CPI of the earlier year). The CPI-U series used here is the BLS's standard index (1982-84 = 100), published as annual averages from 1913 onward - the same data behind every 'in today's money' headline you've ever read.
Why does my number differ slightly from other calculators?
Three honest reasons: some sites use monthly rather than annual CPI (a December-vs-January difference), some use the CPI-Retroactive series the BLS rescaled in 1978, and the current year is always an estimate until the BLS finalizes it. Differences of a percent or two are normal and not a sign anyone is wrong.
What was the worst inflation in US history?
The 1970s: prices nearly doubled across the decade (about 7-8% a year compounded), and single years hit 13%+ in 1979-1980. The fastest single-year spike in the modern series was 2022's post-pandemic surge; the deflation years of the 1930s cut prices but brought the Depression - falling prices are not a bargain.
Does this work for salaries and investments?
For comparing purchasing power across time, yes - a $30,000 salary in 2000 equals about $55,000 today, and that's the honest way to judge a raise across years. For investments, subtract inflation from the nominal return to get the real return: 5% gains in a 3% year is only 2% of actual buying power.