Last updated: May 2026
See how purchasing power erodes over time using historical CPI data, or project what today's prices will look like in the future.
Formula: Adjusted Value = Original × (CPI_end ÷ CPI_start)
The Consumer Price Index (CPI) measures the average change in prices over time for a basket of goods and services. Dividing the end CPI by the start CPI gives the cumulative price multiplier.
CPI data sourced from U.S. Bureau of Labor Statistics (BLS). Anchor points are used for years 1913–2025; intermediate years are linearly interpolated and may differ slightly from official BLS figures.
Year-by-Year Projection
Formula: Future Value = Present × (1 + rate)^years
This tells you how much money you will need in the future to buy the same goods and services that cost a given amount today, assuming a constant annual inflation rate.
Historical Reference — $100 in Year X equals how much today (2025)?
Based on CPI anchor data; 2025 CPI = 320.0.
Related Calculators
⚠️ CPI data is based on published BLS anchor points with linear interpolation for missing years. Results are estimates for educational purposes. Actual purchasing power may differ based on your personal spending basket.
This calculator shows how the purchasing power of money changes over time using historical or projected inflation rates, based on the Consumer Price Index (CPI) methodology used by the U.S. Bureau of Labor Statistics.
Worked example: $100 in 2000 is equivalent to how much in 2026? Using average CPI inflation of ~2.8%/year over that period: $100 x (1.028)^26 = $100 x 2.046 = $204.60. What cost $100 in 2000 now costs roughly $205 in 2026 — meaning the dollar lost about half its purchasing power in 26 years.
The Fed targets 2% annual inflation. At 2%, prices double every 36 years. At 3%, every 24 years. At 7% (roughly the 2022 peak), every 10 years. Use this calculator to understand the real return on savings and investments — a 5% return during 4% inflation is only a 1% real gain.
CPI (Consumer Price Index) measures the average price change across a basket of goods and services including food and energy. Core inflation excludes food and energy because these are highly volatile. The Fed primarily monitors core PCE (Personal Consumption Expenditures) inflation as its preferred measure. When the media reports "inflation is 3.2%," that is typically the CPI headline figure. Core inflation is usually 0.2-0.5% lower during normal times.
Inflation erodes the real value of cash holdings. A savings account earning 2% APY during 3% inflation has a real return of -1% — you are losing purchasing power. To maintain real wealth, your investments must return at least the inflation rate. Historically, equities have returned ~7% real after inflation, making them the primary hedge against inflation over long periods. TIPS (Treasury Inflation-Protected Securities) are designed to match inflation exactly.
The highest sustained inflation in modern U.S. history occurred 1979-1981, peaking at 14.8% in March 1980 during the oil crisis and Federal Reserve tightening under Paul Volcker. The 2021-2022 inflation surge peaked at 9.1% in June 2022 — the highest since 1981. The Fed responded with aggressive rate hikes, bringing inflation down to the 3-4% range by 2023-2024.
Inflation benefits borrowers with fixed-rate debt because they repay loans with dollars that are worth less than when borrowed. A $200,000 mortgage taken out when inflation runs at 4% annually means you are effectively repaying the loan with money worth about 4% less each year in real terms. This is why fixed-rate long-term debt (like a 30-year mortgage) is considered an inflation hedge — the real cost of the debt shrinks as prices rise.
Inflation is not a constant force — it surges during supply shocks and recessions, then moderates during periods of stable growth. Understanding historical inflation helps put today's numbers in context and illustrates why financial plans must account for purchasing power erosion even in low-inflation environments. At just 2% per year — the Fed's stated target — prices double every 36 years.
The table below summarizes average annual CPI inflation by decade and the total cumulative price increase over each period. The 2020–2022 surge was the sharpest since the early 1980s, driven by pandemic-era stimulus, supply chain disruptions, and energy price spikes.
| Period | Avg Annual CPI | Cumulative | Notable Event |
|---|---|---|---|
| 1970s | 7.4% | +107% | Oil crisis / stagflation |
| 1980s | 5.1% | +66% | Volcker rate hikes |
| 1990s | 2.9% | +33% | Stable growth era |
| 2000s | 2.6% | +29% | Housing bubble / GFC |
| 2010s | 1.8% | +20% | Post-recession low |
| 2020–2022 | 5.8% | +17% in 3 yrs | COVID stimulus / supply chain |
| 2023–2024 | 3.4% | Normalizing | Fed rate tightening |
What is inflation?
Inflation is the rate at which the general price level of goods and services rises over time, which corresponds to a fall in the purchasing power of money. When inflation runs at 3%, a basket of goods that costs $100 today will cost $103 in one year. Over time, even moderate inflation significantly erodes the real value of cash and fixed-income assets.
How is inflation measured?
The most common measure is the Consumer Price Index (CPI), published monthly by the Bureau of Labor Statistics. CPI tracks prices for a fixed basket of goods and services — housing, food, transportation, medical care, apparel, and more. The Federal Reserve's preferred measure is the PCE (Personal Consumption Expenditures) price index, which adjusts for changes in consumer behavior as prices shift.
What causes inflation?
Inflation has three primary causes: demand-pull (too much money chasing too few goods), cost-push (rising production costs passed to consumers), and built-in inflation (wage-price spirals). The 2021–2022 surge combined all three: stimulus payments boosted demand, supply chains drove up costs, and labor shortages pushed wages higher. Central banks fight inflation primarily by raising interest rates to cool borrowing and spending.
How does inflation affect savings?
Inflation silently erodes savings held in low-interest accounts. Cash under a mattress loses roughly 2–3% of its real value every year in a normal inflation environment. To preserve purchasing power, your savings must at minimum earn the inflation rate. High-yield savings accounts, I-bonds, and TIPS are designed to keep pace with inflation; long-term equity investments historically outpace it by 5–7 percentage points annually.
What is the difference between real and nominal return?
Nominal return is the stated percentage gain on an investment before adjusting for inflation. Real return is what you actually gain in purchasing power. If your portfolio earned 8% and inflation was 3%, your real return was approximately 5%. Real return is what matters for long-term wealth building — a high nominal return during high inflation may leave you no better off than a lower nominal return during low inflation.