Inflation Explained Without the Jargon: Why Your Number Is Not 3.7% (and How to Find It)
Short answer: the Bureau of Labor Statistics reported that prices were 3.7% higher in September 2026 than a year earlier, but that is an average of a national basket, not your bill. A renter who drives to work can easily have a personal rate near 4.5%, while a homeowner with a fixed mortgage who works from home may sit near 2%. The gap comes from what you buy, where you live and when your bills reset.
On October 14, 2026, BLS published the September Consumer Price Index. The headline was 3.7% over 12 months and 0.6% for the month. This article explains what that number measures, what is inside it, and how to work out your own in about 20 minutes. It is general education, not financial advice.
What the 3.7% actually measures
The CPI follows a basket. BLS says it records about 80,000 prices a month, and the weights come from family spending surveys, so rent, groceries and gas count in proportion to what households typically spend. The index is built so that 1982-84 equals 100; in September 2026 it stood at 336.940, against 324.800 a year earlier. That is the 3.7%. Over five years, from 274.310 in September 2021, the basket is up 22.8%, so $100 then costs about $122.83 now (my arithmetic).
BLS is open about the limits. It says the CPI does not necessarily measure your own experience with price change, and it leaves out income and payroll taxes and investments. For homeowners it tracks what the home would rent for (owners' equivalent rent, up 3.3%), not your mortgage payment.
Inside the average: very different stories
The same release shows how uneven the year was. Gasoline rose 34.2% over 12 months and 9.1% in September alone, which BLS says accounted for over half of the monthly increase. Core inflation, which leaves out food and energy, was 2.6%, and energy was up 20.4%.
| Gasoline | +34.2% |
| Hospital services | +5.6% |
| Electricity | +4.4% |
| Food away from home | +3.5% |
| Rent of primary residence | +2.8% |
| Food at home | +1.8% |
| Used cars and trucks | -1.5% |
| Motor vehicle insurance | -5.0% |
Two households, two different years
To see how the average breaks apart, take two made-up households with the same $4,000 monthly spending, and apply the real September price changes. Ray rents and drives to work: rent $1,400, groceries $600, gasoline $280, dining out $200, car insurance $180, electricity $150, medical care $250, everything else $940. Nia owns her home with a fixed-rate mortgage and works from home: mortgage $1,500, groceries $900, gasoline $90, dining $150, car insurance $160, electricity $220, medical $300, everything else $680.
| Ray: gasoline (7% of spending x 34.2%) | +2.39 points |
| Ray: rent (35% x 2.8%) | +0.98 points |
| Ray: total, all eight lines | about 4.5% |
| Nia: total, mortgage unchanged | about 2.0% |
| Official CPI-U | 3.7% |
Gasoline alone costs Ray about $71 more a month than a year ago for the same driving. Nia is not simply winning: property taxes, home insurance and repairs can still climb, and they are not in this simple math. The point is that the headline cannot know your mix, your place or your timing, such as a lease that holds still for a year and then resets all at once.
Why it can feel worse than the report
A study in the Journal of Political Economy (D'Acunto, Malmendier, Ospina and Weber, 2021) found that households' inflation expectations are driven mainly by the grocery prices they regularly buy, that items bought often seem to matter more than items taking a large share of the budget, and that price increases shift expectations more than equal-sized decreases. The index and your memory measure different things.
Did pay keep up?
BLS reports average hourly earnings of $37.81 in September 2026, up 3.0% from a year earlier, while prices rose 3.7%. BLS says real average hourly earnings fell 0.7% over the 12 months. Over five years the picture is closer: average hourly earnings rose from $30.98 to $37.81 (+22.0%, my arithmetic on BLS data via FRED) against +22.8% for prices. These are averages across millions of workers, so your raise may look different.
Your number in 20 minutes
List 8 to 12 spending categories from a typical month. Find each category's share of the total. Find each price's change over 12 months, using your own bills where you can, or the national figures above where you cannot. Multiply share by change, and add the column. That is your personal rate: an estimate, but it shows which two or three lines drive your year. BLS also offers a free CPI Inflation Calculator, which uses the national urban index, so treat it as a starting point.
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See the guide (PDF) →FAQ
What was inflation in September 2026?
BLS reported that the CPI-U rose 3.7% over the 12 months to September 2026 and 0.6% from August, seasonally adjusted. Core inflation, excluding food and energy, was 2.6%.
Why does my inflation feel higher than the official number?
The CPI is an average of a national basket. Your own rate depends on what you buy, where you live and when bills reset. Research also suggests people weigh frequently bought items, like groceries and gas, heavily.
How do I calculate my personal inflation rate?
Take each spending category's share of your total, multiply it by that price's 12-month change, and add up the results. Use your own bills for the changes where possible.
Did wages keep up with prices in 2026?
On average, not over the latest 12 months. BLS reported average hourly earnings up 3.0% against prices up 3.7%, for a 0.7% drop in real average hourly earnings. Individual results vary.
Sources consulted (all opened and read): U.S. Bureau of Labor Statistics, Consumer Price Index news release for September 2026 (October 14, 2026), including Tables 1 and 2; BLS, Real Earnings, September 2026; BLS, CPI Questions and Answers and CPI Inflation Calculator pages (accessed October 2026); CPI-U and average hourly earnings series via FRED (Federal Reserve Bank of St. Louis); U.S. Energy Information Administration, weekly retail gasoline prices (week of October 12, 2026); D'Acunto, Malmendier, Ospina and Weber, "Exposure to Grocery Prices and Inflation Expectations," Journal of Political Economy 129(5), 2021. Ray and Nia are made up, their budgets are invented, and the personal rates, the $71 figure and the five-year changes are my arithmetic on the published numbers. Educational content only, not financial advice.
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Jairo Oliva Jofer
Digital nomad. Brazilian living in Serbia. Jairo writes honest, no-fluff guides and tells rise and fall stories on the Icarus Paradox channel. See all guides →