St. Louis inflation calculator: CPI-U since 1917

Shelter leads in St. Louis

Shelter is the heaviest group in the CPI basket, 35.625 % of the national CPI-U in the BLS December 2025 weights. In St. Louis its 12-month change of +4.7 % runs ahead of the national +3.2 %, and ahead of the all-items rate of the area. A $1,200 monthly housing cost from August 2022 that had tracked the St. Louis shelter index would be $1,478 now; on the national shelter index it would be $1,451. Individual rents differ: the index follows the average of a sample of units, including those whose rent did not change.

Elsewhere in the basket, food at home rose +0.9 % (nation +1.8 %), recreation -1.0 % and other goods and services +5.3 %. Transportation was +4.2 % and medical care +1.6 %. In the table below, energy and food at home reach September 2026 while all items stop at August 2026: the BLS FAQ notes that food at home and energy are priced every month in all areas.

What October 2025 did to an even-month index

St. Louis is priced in February, April, June, August, October and December. The lapse in appropriations from October 1, 2025 to November 12, 2025 wiped out its October 2025 index. Inside the computation, the BLS carried even-month survey prices forward from August to October, and it published no two-month change for December 2025. The 2025 annual average of the area rests on 5 values. For an October 2025 date, the calculator takes August 2025 and tells you so.

The next consequence comes with the release of November 10, 2026: the October 2026 index for St. Louis will appear without a 12-month change. A contract that adjusts each October needs another reference month or a fallback rule; the cost-of-living adjustment page explains the usual choices.

20 years without a monthly index

The St. Louis index starts in December 1917. Between November 1997 and December 2017 the BLS priced St. Louis only twice a year and publishes no monthly index, only an annual average for each year. If your date falls in that window, the calculator uses the annual average of its year and says so; for a month-precise figure, the Midwest region or the national series, both monthly, is the better base.

Highs, lows and the last two years

The top year in the St. Louis data is 1920, at 18.5 %, with 1947 second at 16.2 %. Prices fell the most in 1921, by 12.6 %. In 2024 the annual rate was 3.3 % and in 2025 2.4 %, against 2.8 % for the Midwest in 2025.