Evaluate real purchasing power using historical U.S. CPI data (1913–2026) or forward and backward flat-rate models.
• U.S. CPI Data: Calculate purchasing power between any two months/years from 1913 to 2026 using official Consumer Price Index data.
• Forward Flat Rate: Estimate future prices and cash erosion based on a projected annual inflation rate.
• Backward Flat Rate: Calculate what a current dollar amount was worth in the past under an assumed average rate.
Calculates the equivalent value of the U.S. dollar in any month from 1913 to 2026. Calculations are based on the average Consumer Price Index (CPI) data for all urban consumers in the U.S.
• Source CPI: 240.007 (2016)
• Target CPI: 332.846 (July 2026)
• Time Span: 10.6 Years
The Consumer Price Index (CPI-U), published by the U.S. Bureau of Labor Statistics (BLS), measures the average monthly change over time in prices paid by urban consumers for a market basket of consumer goods and services (including housing, food, transportation, medical care, education, and energy).
In our calculator, the CPI reference baseline is indexed to 1982–1984 = 100. A CPI value of 314.175 in 2024 indicates that a standard basket of goods that cost $100 in 1983 cost approximately $314.18 in 2024.
Historical CPI calculations reflect actual documented price fluctuations in the United States, including periods of high inflation (such as the 1970s and 2021–2022) and periods of deflation (such as the Great Depression of the 1930s).
Flat-rate calculations model hypothetical constant compound inflation into the future or past using geometric compounding ($FV = PV \times (1 + r)^t$), making it ideal for financial planning and retirement budgeting.
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