U.S. Inflation: What It Is, How It Is Measured and Historical Trends

Inflation is one of the most closely watched indicators of U.S. economic health, shaping decisions by households, businesses, and policymakers. As of July 2026, the headline inflation rate in the United States stood at 3.4 percent over the previous 12 months, while core inflation, which excludes volatile food and energy prices, was 2.5 percent, according to the Bureau of Labor Statistics (BLS) as reported by USAFacts. Understanding what inflation is, how it is measured through the Consumer Price Index (CPI), and how it has evolved over time is essential for interpreting economic news, wage adjustments, and the cost of living.

Key Numbers

• Headline inflation rate: 3.4% (July 2025 to July 2026)
• Core inflation rate: 2.5% (excluding food and energy, July 2025 to July 2026)
• Population coverage: About 90% of the U.S. population is represented by the CPI
• Primary measure: Consumer Price Index (CPI), published monthly by the Bureau of Labor Statistics
• Basket concept: A fixed set of goods and services reflecting typical household spending
• Base period: A reference period used to compare current prices and calculate the index
• Core inflation excludes: Food and energy, which are often volatile
• Effect of inflation: Reduces the purchasing power of the dollar over time

Explanation

Inflation refers to a sustained rise in the general price level of goods and services in an economy over a period of time. When inflation occurs, each unit of currency buys fewer goods and services, meaning the purchasing power of money declines. For households, inflation is most visible in everyday expenses such as groceries, housing, transportation, and medical care. For policymakers, inflation is a key indicator of economic stability and a primary consideration in setting interest rates and fiscal policy.

The most widely used measure of U.S. inflation is the Consumer Price Index, or CPI, produced by the Bureau of Labor Statistics. The CPI tracks the price changes of a representative basket of goods and services that reflects the spending habits of urban consumers, who make up about 90 percent of the U.S. population. The basket includes hundreds of items across categories such as food, housing, apparel, transportation, medical care, recreation, education, and communication. By comparing the cost of this basket over time, the BLS calculates how much prices have risen or fallen.

Economists and analysts often distinguish between headline inflation and core inflation. Headline inflation includes all items in the CPI basket, including food and energy, which can be highly volatile due to weather, geopolitical events, and supply disruptions. Core inflation excludes food and energy to provide a clearer view of underlying, persistent price trends. Both measures are important: headline inflation reflects the actual cost of living, while core inflation helps identify longer-term inflationary pressures.

Definition

Inflation is defined as a general increase in the price of goods and services over time, which reduces the purchasing power of the dollar. This definition is used by the Congressional Research Service and other official sources. Inflation does not mean that all prices rise at the same rate; some items may become cheaper while others become more expensive. Rather, inflation reflects an overall upward movement in the average price level across a broad range of goods and services.

Inflation is defined as a general increase in the price of goods and services over time, which reduces the purchasing power of the dollar.

The opposite of inflation is deflation, a general decline in prices, which can also be harmful to an economy by encouraging consumers to delay purchases and increasing the real burden of debt. Disinflation refers to a slowdown in the rate of inflation, meaning prices are still rising but at a slower pace. The U.S. economy has experienced periods of all three conditions, but moderate positive inflation is generally considered normal and even desirable for a growing economy.

Methodology

Measuring inflation begins with collecting the prices of a large number of goods and services. In the case of households, government statistical agencies create a basket of goods and services that reflects the items consumed by households. The basket does not contain every good or service but is meant to be a good representation of both the types of items and the quantities of items that households typically consume. The Bureau of Labor Statistics updates the basket periodically to reflect changing consumer preferences, but the core methodology remains consistent over time.

Agencies use the basket to construct a price index. First, they determine the current value of the basket by calculating how much the basket would cost at today’s prices, multiplying each item’s quantity by its price today and summing up. Next, they determine the value of the basket in a reference or base period by multiplying each item’s quantity by its base-period price. The price index is then calculated as the ratio of the value of the basket at today’s prices to the value at the base-period prices, often multiplied by 100. This index allows for consistent comparisons of price levels over time.

There is an equivalent but sometimes more convenient formulation to construct a price index that assigns relative weights to the prices of items in the basket. Each item’s weight reflects its importance in total household spending. For example, housing costs typically receive a much larger weight than apparel because housing represents a larger share of consumer budgets. The BLS uses detailed expenditure surveys to determine these weights, ensuring that the CPI accurately reflects real-world spending patterns.

How the Statistic Is Calculated

The Consumer Price Index is calculated through a multi-step process. First, the BLS selects a sample of goods and services that represents the spending patterns of urban consumers. This sample includes thousands of specific items, from rent and gasoline to cereal and medical services. Prices for these items are collected monthly from thousands of retail stores, service establishments, rental units, and online sources across the United States.

Second, the BLS assigns each item a weight based on its share of total consumer expenditures. These weights come from the Consumer Expenditure Survey, which tracks how households actually spend their money. The weights are updated every two years to reflect changes in buying habits. Third, the BLS calculates the cost of the basket in the current month and compares it to the cost of the same basket in a base period. The resulting ratio is the price index. The inflation rate is then calculated as the percentage change in the index over a specific period, usually 12 months.

For example, if the CPI index value was 300 in July 2025 and 310.2 in July 2026, the year-over-year inflation rate would be (310.2 – 300) / 300 × 100 = 3.4 percent. This is exactly the type of calculation that produced the 3.4 percent headline inflation rate reported for July 2026. Core inflation is calculated the same way but excludes the food and energy components from the basket before computing the index.

Historical Data

The history of U.S. inflation shows distinct periods of stability, rapid price increases, and deliberate disinflation. In the 1950s and early 1960s, inflation was generally low and stable, often below 2 percent annually. Beginning in the late 1960s and accelerating through the 1970s, inflation rose sharply due to a combination of expansionary fiscal and monetary policies, oil price shocks, and rising inflation expectations. By the late 1970s and early 1980s, the United States experienced double-digit inflation, which eroded savings and created significant economic uncertainty.

Under Federal Reserve Chair Paul Volcker, the central bank raised interest rates dramatically in the early 1980s to break the inflationary cycle. This policy succeeded in bringing inflation down, but it also caused a severe recession. From the mid-1980s through the 2000s, inflation remained relatively moderate, a period sometimes called the Great Moderation. The 2008 financial crisis led to a brief period of very low inflation and even concerns about deflation, but prices soon stabilized.

The most recent significant inflation episode began in 2021, when pandemic-related supply chain disruptions, labor shortages, and strong consumer demand pushed prices up rapidly. Inflation reached levels not seen in four decades, prompting the Federal Reserve to raise interest rates aggressively in 2022 and 2023. By 2024 and 2025, inflation had moderated substantially, and as of July 2026, headline inflation stood at 3.4 percent, closer to historical norms but still above the Federal Reserve’s long-run target of 2 percent.

Year-over-Year Change

The most common way to report inflation is the year-over-year change, which compares the price level in a given month to the same month one year earlier. This method smooths out seasonal fluctuations and provides a clear picture of the trend. As of July 2026, the year-over-year headline inflation rate was 3.4 percent, meaning that the overall CPI basket cost 3.4 percent more in July 2026 than it did in July 2025. The core inflation rate, which excludes food and energy, was 2.5 percent over the same period.

The difference between headline and core inflation reflects the volatility of food and energy prices. Energy prices, in particular, can swing sharply due to global oil markets, weather events, and geopolitical tensions. Food prices can also be affected by supply chain disruptions, crop conditions, and transportation costs. By excluding these categories, core inflation provides a more stable measure of underlying price pressures, which is why the Federal Reserve pays close attention to it when setting monetary policy.

Year-over-year changes can be influenced by base effects. For example, if prices rose sharply in the prior year, the current year-over-year rate may appear lower even if prices are still increasing month to month. Conversely, if prices fell sharply a year earlier, the current rate may appear higher. Analysts often look at both year-over-year and month-over-month changes to get a complete picture of inflation dynamics.

Factors Behind the Trend

Several factors influence the level and direction of U.S. inflation. On the demand side, strong consumer spending, low unemployment, and rising wages can push prices up as households compete for a limited supply of goods and services. On the supply side, disruptions such as factory shutdowns, shipping delays, labor shortages, and higher input costs can reduce the availability of goods and drive prices higher. The pandemic period of 2021-2022 illustrated how supply chain bottlenecks and pent-up demand can combine to create rapid inflation.

Energy prices play a particularly important role in headline inflation because energy is a direct cost for consumers and an indirect cost for businesses that must transport goods and power facilities. When oil and natural gas prices rise, they feed quickly into gasoline, heating, and electricity prices, which are visible components of the CPI. Food prices are similarly sensitive to weather, global commodity markets, and transportation costs.

Monetary policy is another key factor. The Federal Reserve influences inflation by adjusting the federal funds rate, which affects borrowing costs throughout the economy. When inflation is too high, the Fed raises interest rates to cool demand; when inflation is too low, it lowers rates to stimulate spending. Fiscal policy, including government spending and tax decisions, can also affect inflation by changing the amount of money flowing through the economy. Finally, inflation expectations themselves can become self-fulfilling: if households and businesses expect higher prices, they may demand higher wages and raise prices, locking in inflation.

Why It Matters

Inflation matters because it directly affects the purchasing power of households. When prices rise faster than incomes, families can afford fewer goods and services, and their standard of living may decline. Even moderate inflation erodes the value of savings held in cash or low-interest accounts. For retirees and others on fixed incomes, inflation can be especially harmful because their income does not automatically adjust to rising prices.

Inflation also influences interest rates and financial markets. Lenders demand higher interest rates to compensate for the loss of purchasing power over the life of a loan. The Federal Reserve adjusts its policy rate in response to inflation, which in turn affects mortgage rates, auto loans, credit card rates, and business investment. High or unpredictable inflation creates uncertainty, making it harder for businesses to plan and for households to make long-term financial decisions.

Many government programs and private contracts include cost-of-living adjustments, or COLAs, that are tied to the CPI. Social Security benefits, for example, are adjusted annually based on inflation to help recipients maintain their purchasing power. Union wage contracts, rental agreements, and tax brackets may also be indexed to inflation. Accurate measurement of inflation is therefore essential for the fair administration of these programs and for economic policy more broadly.

Limitations of the Data

The Consumer Price Index is a powerful tool, but it has limitations. First, the CPI represents about 90 percent of the U.S. population, but it does not cover rural households, military personnel, or people in institutions. The spending patterns of these excluded groups may differ from those of urban consumers, so the CPI may not perfectly reflect their inflation experience. Second, the CPI uses a fixed basket of goods and services, which means it may not fully capture changes in consumer behavior when prices change. For example, if the price of beef rises sharply, consumers may switch to chicken, but the fixed basket still weights beef at its original level, potentially overstating the impact of the price increase.

Third, measuring quality changes is difficult. When a product improves in quality, such as a car with better safety features or a computer with more processing power, part of the price increase may reflect higher quality rather than pure inflation. The BLS attempts to adjust for quality changes, but these adjustments are imperfect and can introduce measurement error. Fourth, the CPI does not include all costs that households face, such as income taxes or investment expenses, and it may not fully capture changes in housing costs for homeowners.

Finally, core inflation, while useful for identifying underlying trends, excludes food and energy, which are essential expenses for every household. As a result, core inflation can understate the actual cost-of-living increases faced by consumers when food and energy prices are rising rapidly. For these reasons, economists often look at multiple inflation measures, including the Personal Consumption Expenditures price index produced by the Bureau of Economic Analysis, to get a more complete picture.

Timeline

• 1913: The Bureau of Labor Statistics begins publishing the Consumer Price Index to track cost-of-living changes for urban workers.
• 1970s: Inflation accelerates due to oil shocks, expansionary policies, and rising expectations, reaching double digits by the end of the decade.
• Early 1980s: Federal Reserve Chair Paul Volcker raises interest rates sharply, breaking the inflationary spiral but causing a deep recession.
• 1980s-2000s: Inflation remains moderate, a period known as the Great Moderation.
• 2008-2009: The financial crisis leads to very low inflation and brief deflation concerns.
• 2021-2022: Pandemic-related supply chain disruptions and strong demand push inflation to a four-decade high.
• 2023-2025: Inflation moderates as supply chains heal and the Federal Reserve raises interest rates.
• July 2026: Headline inflation is 3.4 percent and core inflation is 2.5 percent year over year.

Source & Data Date

The primary source for U.S. inflation data is the Bureau of Labor Statistics, which publishes the Consumer Price Index monthly. The current inflation figures cited in this article are for July 2026, as reported by USAFacts and based on BLS data. Additional methodological information comes from the Cleveland Federal Reserve’s Center for Inflation Research and the Congressional Research Service report Introduction to U.S. Economy: Inflation, updated April 1, 2025. The BLS Consumer Price Index Frequently Asked Questions page provides further details on data access and methodology.