Inflation Calculator

What Is Inflation and How Is It Measured?

Inflation is the sustained increase in the general price level of goods and services in an economy over time. When inflation rises, each unit of currency buys fewer goods and services than it did before, a concept known as the erosion of purchasing power. A gallon of milk that cost $2.78 in 2000 costs about $4.30 in 2025. A movie ticket that was $5.39 in 2000 is now over $11. Inflation is not a bug in the economic system; most economists consider moderate inflation (around 2% per year) a sign of a healthy, growing economy.

In the United States, inflation is primarily measured through the Consumer Price Index (CPI), published monthly by the Bureau of Labor Statistics (BLS). The CPI tracks the average change in prices paid by urban consumers for a representative "basket" of approximately 80,000 goods and services across eight major categories: food and beverages, housing, apparel, transportation, medical care, recreation, education and communication, and other goods and services. The BLS collects price data from about 23,000 retail and service establishments and 50,000 housing units in 75 urban areas across the country.

There are two primary versions of the CPI. CPI-U (all urban consumers) covers approximately 93% of the US population and is the most widely cited measure. CPI-W (urban wage earners and clerical workers) covers about 29% of the population and is used specifically for Social Security cost-of-living adjustments (COLAs). A separate measure, the Personal Consumption Expenditures (PCE) price index, published by the Bureau of Economic Analysis, is the Federal Reserve's preferred inflation gauge for monetary policy decisions. PCE tends to run about 0.3 percentage points lower than CPI because it accounts for consumer substitution when prices change.

The concept of "real" versus "nominal" values is central to understanding inflation. Nominal values are stated in current dollars without adjustment. Real values are adjusted for inflation and reflect actual purchasing power. When someone says their salary went from $50,000 to $55,000, that is a 10% nominal increase. But if inflation was 8% over that period, the real increase in purchasing power was only about 2%. This calculator converts between nominal and real dollars using historical CPI data.

How the Inflation Calculator Works

This calculator uses the CPI-U annual average to determine how the purchasing power of the US dollar has changed between any two years from 1913 to 2025. The core formula is:

For example, to find out what $100 in 1990 is worth in 2025 dollars: the CPI in 1990 was 130.7 and the CPI in 2025 is 320.8. So the adjusted amount is $100 × (320.8 / 130.7) = $245.37. This means you would need $245.37 in 2025 to buy what $100 bought in 1990.

The calculator also provides two additional metrics. Cumulative inflation is the total percentage price increase over the entire period: ((CPI_end − CPI_start) / CPI_start) × 100. Average annual inflation is the compound annual growth rate (CAGR) of prices: ((CPI_end / CPI_start)^1/years − 1) × 100. The CAGR smooths out year-to-year volatility to show the average annual rate of price increase.

Key Inflation Terms

Historical US Inflation Rates by Decade

US inflation has varied dramatically across different economic eras. The table below shows the average annual inflation rate for each decade since the 1950s, along with notable economic events that drove price changes.

Since 1913, cumulative inflation in the United States has exceeded 3,100%, meaning goods that cost $1 in 1913 would cost over $32 today. The single highest year was 1918 (17.8%, driven by World War I), while the largest single-year deflation was 1921 (−10.5%).

Practical Inflation Examples

Cumulative vs. Annual Inflation

Understanding the difference between cumulative and annual inflation is important for interpreting this calculator's results. Annual inflation is the percentage increase in the price level over a single year. Cumulative inflation is the total percentage increase over an entire multi-year period.

These two numbers can paint very different pictures. From 2000 to 2025, the average annual inflation rate was about 2.5% — which sounds modest. But cumulative inflation over those 25 years was about 86%, meaning prices nearly doubled. The compounding effect is significant: even low annual rates accumulate substantially over decades. At just 2% annual inflation, prices double every 36 years. At 3%, they double every 24 years.

When evaluating long-term financial decisions — retirement planning, pension values, long-term contracts, or investment returns — always consider cumulative inflation rather than just the annual rate. A bond paying 4% annually might seem attractive, but if cumulative inflation over its 10-year term is 30%, your real return is much lower than the nominal return suggests.

How Inflation Affects Your Finances

Savings erosion: Cash in a savings account loses purchasing power when the interest rate is below the inflation rate. If your savings account pays 0.5% APY and inflation is 3%, your real return is −2.5% per year. Over 10 years, $10,000 in savings loses about 22% of its purchasing power despite growing nominally. High-yield savings accounts, certificates of deposit (CDs), and Treasury Inflation-Protected Securities (TIPS) can help, but rarely outpace inflation by a significant margin.

Wage growth: If your salary does not increase at least as fast as inflation, your real income is declining even if your paycheck looks the same or slightly larger. From 2020 to 2023, cumulative inflation was about 19%, meaning workers who did not receive at least a 19% raise over that period experienced a real wage cut. Negotiating raises that account for inflation is essential for maintaining your standard of living.

Debt: Inflation can actually benefit borrowers with fixed-rate debt. If you took out a 30-year mortgage at 3.5% in 2020 and inflation averages 3% going forward, you are repaying that loan with dollars that are worth less over time. Your monthly payment stays the same nominally, but its real cost decreases each year. This is one reason why moderate inflation is generally considered beneficial for economic growth.

Investments: Over the long term, equities have historically outpaced inflation, with the S&P 500 averaging about 10% annual returns (roughly 7% after inflation). Real estate has averaged 4–5% appreciation. Treasury bonds and savings accounts have often barely kept pace with or lagged inflation. For long-term goals like retirement, maintaining an investment portfolio that outpaces inflation is critical. Use our Compound Interest Calculator to see how different return rates compare against inflation over time.

2026 Inflation Context

After peaking at 9.1% year-over-year in June 2022 — the highest level since November 1981 — US inflation has moderated significantly. The annual CPI rate fell to about 3.0% by mid-2025, though it remains above the Federal Reserve's 2% target. Several factors are shaping the 2026 inflation outlook.

Tariffs and trade policy: New tariffs introduced in 2025 on imported goods from several major trading partners are expected to add upward pressure on consumer prices, particularly for electronics, automobiles, and manufactured goods. The Congressional Budget Office estimated that broad-based tariffs could add 0.3–0.7 percentage points to annual CPI inflation depending on the scope and duration of the trade measures.

Housing costs: Shelter inflation, which makes up about one-third of the CPI basket, has remained elevated even as other categories cooled. Rent and owners' equivalent rent have been slow to reflect the moderation in new lease rates, due to the lag in how the BLS measures housing costs. This component is expected to continue declining gradually through 2026.

Federal Reserve policy: The Fed's target federal funds rate remains elevated as the central bank balances inflation reduction against economic growth. The Fed has signaled it will maintain restrictive monetary policy until confident inflation is sustainably moving toward 2%. Market participants are watching Core PCE (which excludes volatile food and energy prices) as the key metric for future rate decisions.