CPI Report Explained: Inflation, Core CPI, and Percent Change
The July 2026 CPI report is a useful statistics lesson because it turns one headline into several separate questions: What is the Consumer Price Index? What is core CPI? Why are some numbers seasonally adjusted? And how do you calculate the inflation rate from CPI index values?
This CPI report explained guide uses official Bureau of Labor Statistics time-series values to show how the July 2026 inflation numbers work, then turns the same data into student-friendly formulas and interpretation.
Sources: official BLS time series for all items CPI, seasonally adjusted, all items CPI, not seasonally adjusted, core CPI, seasonally adjusted, and core CPI, not seasonally adjusted.
Quick answer: In July 2026, the seasonally adjusted all-items CPI moved from 332.568 to 332.813, an increase of about 0.1% month over month. The not seasonally adjusted all-items CPI moved from 323.048 in July 2025 to 333.918 in July 2026, an increase of about 3.4% year over year.
Table of Contents
What Is the CPI Report?
The CPI report measures changes in prices paid by consumers for a basket of goods and services. CPI stands for Consumer Price Index. If you are looking for a consumer price index explained simply, think of it as a price-level index, not as the price of one item.
An index value does not mean the average item costs that many dollars. It means prices are being compared to an index base period. Inflation is then calculated from how much the index changes over time.
July 2026 CPI Numbers at a Glance
The two most common CPI headlines are the monthly change and the 12-month change. Monthly changes often use seasonally adjusted data. Year-over-year changes often use not seasonally adjusted data.
| Measure | Earlier Value | July 2026 Value | Percent Change |
|---|---|---|---|
| All items CPI, monthly, seasonally adjusted | 332.568 in June 2026 | 332.813 in July 2026 | About 0.1% |
| All items CPI, 12-month, not seasonally adjusted | 323.048 in July 2025 | 333.918 in July 2026 | About 3.4% |
| Core CPI, monthly, seasonally adjusted | 336.065 in June 2026 | 336.789 in July 2026 | About 0.2% |
| Core CPI, 12-month, not seasonally adjusted | 328.980 in July 2025 | 337.133 in July 2026 | About 2.5% |
These numbers are rounded for readability. The exact calculation depends on which CPI series is used and how many decimal places are kept.
How to Calculate Inflation Rate From CPI
The inflation rate is a percent change. That means the same basic formula used in many statistics, economics, and business assignments applies here.
If your question is how is CPI calculated, separate two ideas: BLS constructs the CPI index from a market basket of consumer prices, while students usually calculate the inflation rate from CPI by using the percent change formula.
For the July 2026 12-month all-items CPI change:
New CPI = 333.918
Inflation rate = (333.918 – 323.048) / 323.048 x 100
Inflation rate = 10.870 / 323.048 x 100
Inflation rate = about 3.4%
This is why inflation rate explained questions usually come back to percent change. The CPI index gives the price level. The inflation rate describes how fast that price level changed.
Core CPI Explained
Core CPI usually means CPI for all items except food and energy. The reason is not that food and energy are unimportant. They are very important to households. The reason is that food and energy prices can move sharply from month to month, which can make underlying price trends harder to see.
All-items CPI
Includes the broad consumer basket, including food and energy. This is often the main inflation headline.
Core CPI
Excludes food and energy to help analysts study underlying price movement without two volatile categories.
In July 2026, the seasonally adjusted core CPI moved from 336.065 to 336.789, or about 0.2% month over month. The not seasonally adjusted core CPI moved from 328.980 in July 2025 to 337.133 in July 2026, or about 2.5% year over year.
Seasonally Adjusted vs Not Seasonally Adjusted CPI
Seasonally adjusted data tries to remove predictable seasonal patterns. For example, some prices tend to move in regular seasonal ways because of holidays, weather, travel patterns, or school-year timing.
Not seasonally adjusted data keeps the observed index values without that adjustment. This is why CPI reports often use different series for different questions.
| Question | Common CPI Series Choice | Why |
|---|---|---|
| What changed from last month? | Seasonally adjusted | It helps compare adjacent months after removing predictable seasonal movement. |
| What changed from the same month last year? | Not seasonally adjusted | Same-month comparison already controls for many seasonal patterns. |
| What index value appears in a contract or adjustment rule? | Depends on the rule | Always use the exact series specified by the assignment, contract, or data source. |
Statistics Lessons From the CPI Report
The CPI report is not only an economics story. It is also a compact statistics example.
| Statistics Concept | CPI Example | Student Mistake to Avoid |
|---|---|---|
| Percent change | Inflation rate is calculated from index movement. | Subtracting index values and calling the difference a percent. |
| Index numbers | CPI values represent a price level relative to a base period. | Thinking CPI 333.918 means an item costs $333.918. |
| Data definitions | All-items CPI and core CPI answer different questions. | Comparing the two without explaining what core CPI excludes. |
| Seasonal adjustment | Monthly and 12-month changes may use different series. | Mixing seasonally adjusted and not adjusted numbers without saying so. |
| Rounding | Published percentages may be rounded from more precise index values. | Expecting every rounded table to reproduce exactly from rounded inputs. |
If your assignment asks you to interpret CPI, start by naming the exact series, the time period, the old value, the new value, and whether you are calculating a monthly or 12-month change.
For formula checks and related statistics work, use Statskan’s statistics calculators hub or the normal distribution calculator when your assignment moves from index interpretation into probability or z-score questions.
Need Help With CPI, Inflation, or Statistics Homework?
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Get Statistics Homework Help Ask an Online Tutor View PricingFrequently Asked Questions
The CPI report measures changes in consumer prices using the Consumer Price Index. It summarizes how prices changed across a basket of goods and services over time.
CPI inflation is calculated as percent change: subtract the old CPI from the new CPI, divide by the old CPI, and multiply by 100.
Core CPI is CPI for all items except food and energy. Analysts use it to study underlying price movement without two categories that can be especially volatile month to month.
CPI is an index level. The inflation rate is the percent change in that index over a chosen time period.
Seasonal adjustment tries to remove predictable seasonal patterns so adjacent months can be compared more clearly.
Yes. CPI data are useful for assignments on percent change, index numbers, time series, seasonal adjustment, data interpretation, and economic statistics.
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