US inflation is 3.7% on one measure and 2.6% on another, and soaring gasoline prices explain most of the gap. Here is what “headline” and “core” inflation measure, why economists are watching both this week, and what they mean for your budget.
Key takeaways
- Headline inflation counts everything a typical household buys. Core inflation leaves out food and energy because their prices swing so much.
- In September, US headline inflation was 3.7% over 12 months and core was 2.6%. Most of the gap came from gasoline, which was up 34.2% on the year.
- Your own inflation rate depends on how much of your budget goes on fuel and energy. For a heavy driver it can sit well above the official figure.
The news in brief
On October 27, Reuters published its quarterly poll of more than 500 economists. They expect high inflation to last well into 2027. They raised their 2027 inflation forecasts for 31 of the 50 economies covered, including the US. Crude oil has stayed above $100 a barrel since October 7, and Reuters reports it is up more than 60% since the war with Iran began almost eight months ago. Morgan Stanley’s global chief economist, Seth Carpenter, told Reuters that higher energy prices are now spreading into core inflation measures.
The most recent US figures show why that matters. The Bureau of Labor Statistics (BLS) reported on October 14 that consumer prices rose 0.6% in September alone and 3.7% over the previous 12 months. The energy index was up 20.4% on the year. The BLS said gasoline, up 9.1% in September alone, accounted for over half of that month’s increase. Core prices, which exclude food and energy, rose 0.3% in the month and 2.6% over the year.
The Federal Reserve’s policy committee meets on October 27–28. Core inflation is one of the measures it weighs most carefully when deciding on interest rates.
The basic idea, explained
Statisticians measure inflation by tracking the price of a large “basket” of goods and services: rent, groceries, car insurance, haircuts, gasoline, electricity and much more. Each item is weighted by how much the average household spends on it. If the whole basket costs 3.7% more than a year ago, headline inflation is 3.7%. (We explained the basics in what inflation is and why it hits your wallet.)
Core inflation uses the same basket minus food and energy. Those two are left out not because they are unimportant, since everyone eats and most people drive, but because their prices are very volatile. A hurricane, a poor harvest or a conflict in an oil-producing region can push them up or down by double digits within weeks, and the move often reverses later.
Here is an analogy. Imagine checking your weight every morning. Some days you are up two pounds because of a salty dinner or a hot day. That is like headline inflation: accurate, but noisy. If you averaged out the water swings, you would see your underlying trend, and that is what core inflation tries to show. A doctor cares about the trend. You still feel the heavy days.
That is why central banks watch core so closely. Interest-rate changes take many months to work through the economy, so policymakers try not to react to price spikes that may fade on their own. The worry economists described this week is a different situation: expensive fuel starts leaking into everything else. Delivery firms raise fees, airlines raise fares, and manufacturers pass on higher transport costs. When that happens, core inflation rises too, and it tends to be stickier. (See our breakdown of what’s really in the price of a gallon of gas.)
A worked example
Official inflation is an average. Your own rate depends on what you buy. Take a household that spends $5,000 a month, split three ways. To keep the math simple, we apply the September 12-month BLS rates for gasoline, food and core items to each slice:
| Spending category | A year ago | 12-month change | Today | Extra per month |
|---|---|---|---|---|
| Gasoline | $300 | +34.2% | $402.60 | +$102.60 |
| Food | $700 | +2.5% | $717.50 | +$17.50 |
| Everything else (core) | $4,000 | +2.6% | $4,104.00 | +$104.00 |
| Total | $5,000 | +4.48% | $5,224.10 | +$224.10 |
The math: $224.10 ÷ $5,000 = 0.0448, or about 4.5%. This household’s personal inflation rate is higher than the official 3.7% because gasoline takes up 6% of its budget, and gasoline rose fastest. Gasoline makes up less than half of the extra $224 a month, but it is the part that moved most.
Now run the same household through a different year in which gasoline fell 10% and everything else behaved the same. The gas bill drops to $270, the total comes to $5,091.50, and personal inflation is about 1.8% ($91.50 ÷ $5,000). The core part of the budget rose by the same $104 a month in both scenarios. Only the volatile part changed. That is the gap between headline and core in miniature.
Over a full year, the extra $224.10 a month adds up to about $2,689. If income rose less than 4.5% over the same period, this household’s purchasing power fell, even if its paycheck went up.
What you can do
This is general information, not financial advice.
- Estimate your own rate. Compare last year’s and this year’s spending in three or four big categories from your bank or card statements. It takes about 20 minutes and shows where price increases are actually reaching you.
- Budget energy as a range, not a fixed number. Because fuel prices swing so much, set aside a buffer above your average monthly gas and utility costs instead of assuming last month’s bill will repeat.
- Look at the volatile line items first. Combining trips, carpooling or checking whether your utility offers budget billing can trim the categories that are rising fastest.
- Compare your savings rate with inflation. Money earning less than the inflation rate loses purchasing power each year. Check what your savings account pays against both headline and core inflation.
- Watch core, not just headline. If core inflation starts climbing, higher prices are spreading beyond the gas pump. That often means interest rates stay higher for longer, which matters for borrowing costs.
Key terms
- Headline inflation: the change in the price of the full consumer basket, including food and energy. In the US it is reported monthly in the Consumer Price Index (CPI).
- Core inflation: the same measure excluding food and energy, used to see the underlying trend in prices.
- Pass-through: when a rise in one cost, such as fuel, gets passed on into the prices of other goods and services.
Sources
- U.S. Bureau of Labor Statistics, Consumer Price Index – September 2026 (released October 14, 2026)
- Kiplinger, September CPI Report Shows Inflation Remains Red-Hot
- Reuters poll via GV Wire, High Inflation to Persist Globally Into Next Year, Reuters Poll Shows (October 27, 2026)
- Federal Reserve, October 2026 calendar
Written by The Daily Economy editorial team with AI assistance and checked against the sources above. Read our editorial policy.