September CPI 3.7%: gasoline up 9.1% did over half the work
The Consumer Price Index rose 0.6% in September 2026 and 3.7% over 12 months, BLS said on October 14. Core was 2.6%. The arithmetic from the index levels.
- What happened
- The Bureau of Labor Statistics published the September 2026 Consumer Price Index on October 14, 2026. All items rose 0.6% on the month, seasonally adjusted, and 3.7% over the 12 months to September, up from 3.4% in August. Core, which excludes food and energy, rose 0.3% on the month and 2.6% over the year.
- Why
- Gasoline rose 9.1% in September alone, seasonally adjusted, and BLS says it accounted for over half of the monthly all-items increase. Energy as a whole is up 20.4% over 12 months. Strip it out and the picture is a slow drift upward in core, from 2.4% to 2.6%.
- The numbers that matter
- 3.7%All items CPI-U, 12 months to September 20260.6%All items, August to September 2026, seasonally adjusted2.6%Core CPI, 12 months to September 2026336.940CPI-U index level, September 2026, not seasonally adjusted
- Why it matters
- The index level means $1,000 of the goods and services a typical urban household bought in September 2025 cost $1,037.38 in September 2026. Energy did most of it: a $300 monthly energy bill a year ago is $361.20 at the September rate.
- What happens nextas we saw it on 16 Oct 2026
- The October 2026 CPI is scheduled for Tuesday, November 10, 2026, at 8:30 a.m. ET, according to the BLS release schedule.
Energy at 20.4% is the outlier; every other main group sits between 2.5% and 3.7%.
| Energy | 20.4% |
|---|---|
| All items | 3.7% |
| Shelter | 3.2% |
| Core (less food and energy) | 2.6% |
| Food | 2.5% |
The Consumer Price Index for September 2026 rose 0.6% on the month, the largest monthly increase in the three months the Bureau of Labor Statistics prints side by side in its table, and 3.7% over 12 months. The Bureau published the figures on Wednesday, October 14, 2026, at 8:30 a.m. ET, on schedule. The 12-month rate was 3.4% in August.
One line in the release explains most of it. The index for gasoline rose 9.1% in September, seasonally adjusted, and BLS states that this accounted for over half of the monthly all-items increase. Without the energy column, the report reads as a slow drift: the core index rose 0.3% for a second month and its 12-month rate moved from 2.4% to 2.6%.
The site's preview, what is published on October 14, set out the mechanics and the base index. This piece reports what arrived and does the arithmetic the index levels now allow.
The figures, as printed
The CPI-U for all items increased 0.6% in September 2026 on a seasonally adjusted basis, after 0.4% in August and 0.1% in July. Before seasonal adjustment, the index rose 3.7% over the 12 months ending September 2026. The not-seasonally-adjusted index level was 336.940 (1982–84 = 100), against 334.980 in August 2026 and 324.800 in September 2025. Source: BLS, CPI news release and Table 1 for September 2026, released October 14, 2026.
The index for all items less food and energy rose 0.3% in September, matching August, and 0.2% in July. Over 12 months it rose 2.6%, from 2.4% in the 12 months to August. Core carries a relative importance of 79.075% of the index as of August 2026.
| Category | Jul. 2026 (SA) | Aug. 2026 (SA) | Sep. 2026 (SA) | 12 months to Sep. 2026 (NSA) |
|---|---|---|---|---|
| All items | 0.1% | 0.4% | 0.6% | 3.7% |
| Food | 0.1% | 0.1% | 0.0% | 2.5% |
| Food at home | −0.1% | 0.0% | −0.1% | 1.8% |
| Food away from home | 0.3% | 0.3% | 0.2% | 3.5% |
| Energy | −1.5% | 2.1% | 5.2% | 20.4% |
| Gasoline (all types) | −2.9% | 3.9% | 9.1% | 34.2% |
| Electricity | 0.1% | −0.2% | 0.2% | 4.4% |
| All items less food and energy | 0.2% | 0.3% | 0.3% | 2.6% |
| Shelter | 0.1% | 0.3% | 0.4% | 3.2% |
| Rent of primary residence | 0.3% | 0.2% | 0.2% | 2.8% |
| Owners' equivalent rent | 0.3% | 0.2% | 0.3% | 3.3% |
| Medical care services | 0.6% | −0.2% | 0.3% | 2.5% |
| Transportation services | 0.3% | 0.5% | 0.6% | 2.7% |
| Used cars and trucks | 0.4% | 0.4% | 0.7% | −1.5% |
| New vehicles | 0.1% | 0.3% | 0.2% | 0.6% |
| Apparel | 0.1% | 0.0% | 0.3% | 3.4% |
What moved: energy, and almost only energy
The energy index rose 5.2% in September, seasonally adjusted, after 2.1% in August and a 1.5% fall in July. Gasoline rose 9.1% seasonally adjusted; BLS notes that before seasonal adjustment, gasoline rose 6.5% in the month. Fuel oil rose 15.3%. Electricity rose 0.2% and natural gas fell 0.3%. Over 12 months, energy is up 20.4%, gasoline 34.2%, electricity 4.4% and natural gas 5.0%. Energy's relative importance in the index is 7.418%.
Energy's share of the index (7.418%) multiplied by its monthly change (5.2%) gives 0.386 percentage points of contribution, against an all-items rise of 0.6%. That is a rough weight-times-change estimate, not the BLS contribution calculation, which uses the relative importance of the prior month and unrounded indexes; but it is consistent with the Bureau's own statement that gasoline alone accounted for over half of the monthly increase. Inputs: Table 1 relative importance (August 2026) and seasonally adjusted September changes.
The food index was unchanged in September. Food at home fell 0.1%, with milk down 2.0% and beef down 1.0%; food away from home rose 0.2%. Over 12 months food is up 2.5%, with food at home 1.8% and food away from home 3.5%. Shelter rose 0.4% on the month, with owners' equivalent rent up 0.3% and rent up 0.2%, and is up 3.2% over the year. Lodging away from home rose 2.0% in the month.
Inside core, the September risers were lodging away from home (2.0%), airline fares (1.2%), used cars and trucks (0.7%), hospital services (0.7%), education (0.6%), recreation (0.5%) and apparel (0.3%). Prescription drugs fell 1.2% and communication fell 0.2%. Over 12 months, airline fares are up 22.4%, the one core item moving at anything like energy's pace. The piece on core versus headline explains why the two measures are reported separately.
The arithmetic from the index levels
The preview gave the September 2025 index as 324.800 and said the 12-month rate would be whatever the September 2026 level divided by that number produced. Table 1 confirms the base. The rest is division.
Inputs: CPI-U all items NSA, September 2026 = 336.940; September 2025 = 324.800 (both from Table 1, released October 14, 2026). 336.940 − 324.800 = 12.140 index points. 12.140 ÷ 324.800 = 0.03738, or 3.74%. BLS publishes one decimal, so 3.7%. The month-on-month change before seasonal adjustment is 336.940 ÷ 334.980 = 1.00585, or 0.6%, the same as the seasonally adjusted figure to one decimal.
A 12-month change rounds to 3.8% once the index reaches 324.800 × 1.0375 = 336.98. The actual level was 336.940, so 3.7% was the published figure by a margin of 0.04 points, roughly one hundredth of one percent of the index. The boundary on the other side, below which the figure would have rounded to 3.6%, is 324.800 × 1.0365 = 336.655. September sat in the upper part of the 3.7% band. This is the arithmetic the preview said to expect, applied to the published level.
The FOMC set the federal funds target range at 3.75%–4.00% on September 16, 2026. Against a 12-month CPI of 3.7%, the ex-post gap is between 0.05 and 0.30 percentage points. Against core at 2.6% it is between 1.15 and 1.40 points. This is subtraction of a backward-looking inflation figure from a current policy rate, not a measure of the Federal Reserve's own preferred gauge, which is PCE inflation; the PCE versus CPI piece covers that difference.
What it means for your money
The index level translates directly into household arithmetic. The CPI-U is a basket priced in 75 urban areas each month, so the numbers below are for the average urban basket, not for any particular household. Your own weights, especially on gasoline and rent, decide how far you sit from the average.
Inputs: 336.940 ÷ 324.800 = 1.03738. Multiply $1,000 by that ratio and the result is $1,037.38. For the energy slice alone, a $300 monthly energy bill in September 2025 scales by 1.204 to $361.20; $200 of gasoline scales by 1.342 to $268.40. Food scales by 1.025, so $1,000 of groceries and meals out becomes $1,025. The household that spends little on fuel had a year far closer to 2.6% than 3.7%.
The second use is the nominal-versus-real test on savings. A deposit paying 3.7% over the 12 months to September 2026 kept pace with the all-items index and gained nothing in purchasing power. One paying 2.6% kept pace with core but lost ground against the full basket, including the fuel in it. The yield that matters to any particular household is the one measured against the basket that household actually buys; the inflation and your savings piece sets out the mechanism.
The third use is the Social Security adjustment. The cost-of-living adjustment for benefits paid from January is set from the CPI-W, not the CPI-U. The September release puts the CPI-W index at 330.654, up 3.9% over 12 months. The formula uses the third-quarter average rather than a single month, and the COLA piece walks through the calculation.
What this release does not settle
One month of a 0.6% print does not establish a trend, and the series itself warns against reading it that way: July was 0.1%, August 0.4%, September 0.6%, and the difference between them is almost entirely gasoline, which moved −2.9%, 3.9% and 9.1% in the same three months. The one month is not a trend piece applies.
Nor does the 12-month figure describe the pace of price rises now. It describes the whole year from September 2025 to September 2026, including months that were already published. The marginal information in this release is September alone: 0.6% on the headline, 0.3% on core, and 5.2% on energy. Readers who want to know how the index is assembled, what seasonal adjustment does and why the 12-month and monthly figures can point in different directions will find that in how the CPI is built.
Sources
- Consumer Price Index Summary — September 2026 (news release, published October 14, 2026)Bureau of Labor Statistics · Oct 16, 2026 · Primary source
- Table 1. Consumer Price Index for All Urban Consumers (CPI-U): U.S. city average, by expenditure category — September 2026Bureau of Labor Statistics · Oct 16, 2026 · Primary source
- Schedule of Releases for the Consumer Price IndexBureau of Labor Statistics · Oct 16, 2026 · Primary source
- Consumer Price Index Summary — August 2026U.S. Bureau of Labor Statistics · Sep 11, 2026 · Primary source
- FOMC statement, September 16, 2026Federal Reserve Board · Sep 16, 2026 · Primary source
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