Inflation Calculator
Convert historical dollar values using US CPI data, or project future purchasing power.
Data source: US BLS CPI-U annual averages (1913–2024)
Inflation Summary
Value in 2024
$2,400.15
Cumulative Inflation
140.02%
Annualized Rate
2.61%
Purchasing Power Over Time
Value of $1,000.00 from 1990 to 2024 in today's dollars
How Inflation Erodes Purchasing Power
Inflation is the rate at which the general level of prices for goods and services rises over time. As prices increase, each unit of currency buys fewer goods and services — this is known as the erosion of purchasing power. For example, $1,000.00 in 1990 had the same purchasing power as approximately $2,400.00 in 2024.
The US Bureau of Labor Statistics measures inflation through the Consumer Price Index (CPI-U), which tracks price changes in a representative basket of goods and services purchased by urban consumers. The CPI covers food, housing, transportation, medical care, recreation, and education — representing the spending patterns of roughly 93% of the US population.
The CPI Formula
Adjusted Value = Original Amount × (CPItarget / CPIbase)
Where CPItarget is the index value in the destination year and CPIbase is the index value in the starting year. Both values use the 1982–84 base period where CPI = 100.
When Projections Diverge from Reality
Future inflation projections assume a constant annual rate, but real inflation is volatile. The US experienced near-zero inflation in 2015 (0.1%) and over 8% inflation in 2022. Long-run averages — historically around 3–4% — smooth out these spikes but can still diverge significantly from any individual decade. Projections are most useful for setting a planning baseline, not for precise predictions.
Supply shocks (oil embargoes, pandemics), monetary policy changes, and demand surges can all cause inflation to deviate sharply from any projected rate. When planning for retirement or long-term savings, it is prudent to model both a conservative scenario (3%) and a higher scenario (5–6%) to understand the range of outcomes.
Frequently Asked Questions
How does this inflation calculator work?
In Historical mode, the calculator uses US Bureau of Labor Statistics CPI-U annual averages from 1913 to the present. It divides the CPI of the target year by the CPI of the starting year, then multiplies by your original amount. In Future Projection mode, it uses the compound interest formula: Adjusted Value = Amount ÷ (1 + rate)^years to show how purchasing power erodes over time.
What is the CPI and why does it measure inflation?
The Consumer Price Index (CPI) tracks the average price of a "basket" of goods and services that typical American households buy — including food, housing, transportation, and medical care. When the CPI rises, each dollar buys less, which is what we call inflation. The US BLS CPI-U (Urban Consumers) series used here covers about 93% of the US population.
Why does inflation erode purchasing power?
When the overall price level rises, the same nominal amount of money buys fewer goods and services. For example, $100 in 1980 had the same purchasing power as roughly $374 in 2024, meaning prices have risen about 274% over that period. Savings kept in cash lose real value during inflationary periods unless they earn a return that exceeds the inflation rate.
When should I use Historical vs. Future Projection mode?
Use Historical mode to understand how prices have changed in the past — for example, comparing salaries across decades or understanding the real value of historical figures. Use Future Projection mode for financial planning: estimating how much you will need to maintain your current lifestyle in retirement, or how inflation will affect a fixed income stream over time.
How accurate is the future projection?
Future projections are estimates based on a constant annual inflation rate that you supply. Actual inflation varies year to year — the US historical average is roughly 3–4% per year over the long run, but rates can spike (as in 2021–2022) or stay very low (as in 2015). The projection is a planning tool, not a guarantee. For conservative planning, use a rate slightly above the long-run average.