Historical Inflation & Purchasing Power Calculator
Find out what any dollar amount from the past is worth in today's money.
Uses US CPI data from 1913 to 2025.
What Is the Consumer Price Index (CPI)?
The Consumer Price Index, published by the U.S. Bureau of Labor Statistics (BLS), is the most widely used measure of inflation in the United States. It tracks the average change in prices paid by urban consumers for a representative basket of goods and services — including food, housing, transportation, medical care, clothing, and recreation.
The BLS surveys prices on roughly 80,000 items each month across 75 urban areas. The result is a single number that tells you how prices have moved relative to a base period (currently 1982–1984 = 100).
How the Purchasing Power Formula Works
To find what a dollar amount from year A is worth in year B, the formula is simple:
Equivalent Value = Original Amount × (CPI in Year B ÷ CPI in Year A)
For example: $100 in 1970 (CPI = 38.8). In 2024 (CPI = 314.5): $100 × (314.5 ÷ 38.8) = $810.57. That is, prices increased roughly 8× from 1970 to 2024.
Notable Inflation Periods in U.S. History
- 1920s: Post-WWI inflation followed by the Roaring Twenties deflationary period. Prices actually fell during the 1920s and into the Great Depression.
- Great Depression (1929–1933): Severe deflation. Prices fell roughly 25%. A dollar bought more, but most people had no dollars to spend.
- World War II (1941–1945): Wartime rationing and price controls kept inflation moderate, but it spiked after controls were lifted in 1946–1947.
- 1970s Stagflation: The most painful peacetime inflation in U.S. history. Oil embargoes, loose monetary policy, and wage-price spirals pushed inflation to 14.8% in 1980. The Fed under Paul Volcker raised interest rates to 20% to break it.
- 2021–2023 Spike: The COVID-19 pandemic, supply chain disruptions, and massive government stimulus triggered the highest inflation since the early 1980s, peaking at 9.1% in June 2022.
Practical Uses for This Calculator
Use this to negotiate a salary adjustment for inflation, understand the real cost of historical events, compare home prices across decades, or evaluate whether your retirement savings are keeping pace with purchasing power erosion. A raise that matches inflation means your purchasing power stayed the same — it takes a raise above inflation to actually get ahead.