CPI Inflation Calculator - Consumer Price Index
Enter a dollar amount and two years to see how purchasing power has changed between them. This calculator uses official annual-average CPI-U data from the U.S. Bureau of Labor Statistics covering every year from 1913 to 2025. You get the inflation-adjusted equivalent value, the total cumulative inflation percentage, and the compound annual growth rate (CAGR) of prices over the period. Switch the direction to deflate a future value back to past dollars.
What is the Consumer Price Index (CPI)?
The Consumer Price Index (CPI) is a measure of the average change over time in the prices paid by urban consumers for a representative basket of goods and services. The U.S. Bureau of Labor Statistics publishes CPI-U (for All Urban Consumers) monthly; it is the most widely cited inflation measure in the United States and covers roughly 93 percent of the U.S. population. The basket includes housing, food, transportation, medical care, apparel, recreation, and education. Because prices in that basket fluctuate over time, a dollar buys different quantities of goods in different years, and the CPI captures that drift.
How the inflation adjustment is calculated
To adjust a dollar amount from one year to another, the calculator divides the CPI of the target year by the CPI of the base year and multiplies the result by the original amount: Adjusted value = Original amount x (CPI target year / CPI base year). The cumulative inflation rate over the period is (CPI target - CPI base) / CPI base, expressed as a percentage. The annualised rate is the compound annual growth rate of the CPI: (CPI target / CPI base)^(1/years) - 1. Purchasing power change is the inverse: each dollar gained or lost the fraction 1 - (CPI base / CPI target) of its buying power over the period.
Forward vs. backward inflation adjustment
A forward adjustment answers: "What would $X from year A be worth in year B if it had kept pace with inflation?" That is useful for comparing wages, prices, or costs across different eras. A backward adjustment answers: "What past amount had the same purchasing power as $X today?" That is useful for historians or economists who want to express modern amounts in historical terms. Both use the same CPI ratio; the only difference is which year appears in the numerator and which in the denominator.
Historical U.S. inflation context
U.S. prices have not risen smoothly. The 1920s saw brief deflation after World War I, and the Great Depression pushed prices down sharply through the 1930s. World War II and its aftermath caused rapid rises, and the oil shocks of the 1970s produced the highest peacetime inflation in modern U.S. history, peaking above 14 percent in 1980. The Federal Reserve under Paul Volcker broke that cycle by sharply raising interest rates, and inflation fell steadily through the 1980s and 1990s. From roughly 2010 to 2020, annual inflation rarely exceeded 2 percent. The COVID-19 pandemic and subsequent supply-chain disruptions pushed the annual rate above 8 percent in 2022, its highest since 1981, before easing through 2023 to 2025.
U.S. inflation by decade (annual average CPI-U)
| Decade | Avg CPI-U | Approx. annualised rate | Notable events |
|---|---|---|---|
| 1910s | 13.1 | ~6.1%/yr | World War I price surge |
| 1920s | 17.1 | -1.5%/yr | Post-war deflation then stability |
| 1930s | 13.9 | -2.6%/yr | Great Depression deflation |
| 1940s | 19.4 | ~5.6%/yr | World War II rationing, post-war surge |
| 1950s | 27.0 | ~2.1%/yr | Korean War bump, then moderate |
| 1960s | 31.7 | ~2.8%/yr | Vietnam-era spending begins |
| 1970s | 60.6 | ~7.4%/yr | Oil shocks, stagflation peak |
| 1980s | 118.3 | ~5.5%/yr | Volcker disinflation |
| 1990s | 152.4 | ~3.0%/yr | Slow steady decline in inflation |
| 2000s | 195.4 | ~2.6%/yr | Housing bubble, GFC |
| 2010s | 240.0 | ~1.8%/yr | Post-GFC low inflation era |
| 2020s | 295.0 | ~6.2%/yr (so far) | COVID supply shocks, 2022 surge |
Average annual CPI-U index value and approximate annualised inflation rate for each decade, based on BLS data.
Frequently asked questions
What is the difference between CPI-U and CPI-W?
CPI-U covers all urban consumers (about 93% of the U.S. population), while CPI-W covers only urban wage earners and clerical workers (about 29%). CPI-U is the most widely cited general inflation measure. The Social Security Administration uses CPI-W for cost-of-living adjustments to benefits. This calculator uses CPI-U.
Why does this calculator use annual averages rather than monthly CPI?
Annual average CPI values smooth out seasonal price swings, making year-to-year comparisons cleaner and more representative. If you need to adjust for a specific month rather than a full year, use the official BLS Inflation Calculator at bls.gov, which provides monthly resolution back to 1913.
Does the CPI measure the same basket of goods every year?
The basket is periodically updated to reflect changes in consumer spending patterns, and the weights assigned to each category are revised roughly every two years. The BLS also applies quality-adjustment procedures, so if a car gains more features at the same price, it does not count as inflation. These methodological refinements mean the index is not a pure fixed-basket measure.
How is this different from the GDP deflator or PCE price index?
The GDP deflator covers all goods and services in the economy, including business and government purchases. The Personal Consumption Expenditures (PCE) price index covers only consumer spending but uses a different formula (chained) and a broader basket than CPI. The Federal Reserve targets PCE inflation, not CPI. CPI is used for indexing Social Security, federal tax brackets, Treasury Inflation-Protected Securities (TIPS), and many wage contracts.
How accurate is the CPI as a measure of the inflation I actually experience?
The CPI represents the average urban consumer. Your personal inflation rate may differ based on your spending patterns. If you spend a high share of your income on housing or healthcare, you likely experience higher inflation than CPI suggests, because those categories have outpaced the overall index for decades. If you spend heavily on electronics or clothing, your personal rate may be lower, as those categories have often seen price declines.