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CPI-U and the TIPS reference CPI

CPI-U for August 2026, not seasonally adjusted, was 334.980, 3.4% above the same month a year earlier (stored by 500metrics on ). The reference CPI for TIPS on is 333.91800.

CPI-U, August 2026

334.980

1982-84 = 100 · not seasonally adjusted

Change from a year earlier

3.4%

Ours, from the published index

TIPS reference CPI for each day of October 2026

Reference CPI by day, October 2026 (from CPI-U of July 2026 and August 2026)
DateReference CPI
333.91800
333.95226
333.98652
334.02077
334.05503
334.08929
334.12355
334.15781
334.19206
334.22632
334.26058
334.29484
334.32910
334.36335
334.39761
334.43187
334.46613
334.50039
334.53465
334.56890
334.60316
334.63742
334.67168
334.70594
334.74019
334.77445
334.80871
334.84297
334.87723
334.91148
334.94574

TIPS reference CPI for each day of September 2026

Reference CPI by day, September 2026 (from CPI-U of June 2026 and July 2026)
DateReference CPI
333.95200
333.95087
333.94973
333.94860
333.94747
Show 25 more rows
DateReference CPI
333.94633
333.94520
333.94407
333.94293
333.94180
333.94067
333.93953
333.93840
333.93727
333.93613
333.93500
333.93387
333.93273
333.93160
333.93047
333.92933
333.92820
333.92707
333.92593
333.92480
333.92367
333.92253
333.92140
333.92027
333.91913

CPI-U by month

CPI-U, U.S. city average, all items, not seasonally adjusted, newest first
MonthCPI-UChange from a year earlier
August 2026334.9803.4%
July 2026333.9183.4%
June 2026333.9523.5%
May 2026335.1234.2%
April 2026333.0203.8%
March 2026330.2133.3%
February 2026326.7852.4%
January 2026325.2522.4%
December 2025324.0542.7%
November 2025324.1222.7%
September 2025324.8003.0%
August 2025323.9762.9%
July 2025323.0482.7%
Show 23 more rows
MonthCPI-UChange from a year earlier
June 2025322.5612.7%
May 2025321.4652.4%
April 2025320.7952.3%
March 2025319.7992.4%
February 2025319.0822.8%
January 2025317.6713.0%
December 2024315.6052.9%
November 2024315.4932.7%
October 2024315.6642.6%
September 2024315.3012.4%
August 2024314.7962.5%
July 2024314.5402.9%
June 2024314.1753.0%
May 2024314.0693.3%
April 2024313.5483.4%
March 2024312.3323.5%
February 2024310.3263.2%
January 2024308.4173.1%
December 2023306.7463.4%
November 2023307.0513.1%
October 2023307.6713.2%
September 2023307.7893.7%
August 2023307.0263.7%

Source: U.S. Bureau of Labor Statistics, Consumer Price Index. Observed .

How the reference CPI is computed

The principal of a Treasury Inflation-Protected Security moves with CPI-U, not seasonally adjusted, with a lag. The reference CPI for day d of a month is the CPI-U of three months earlier plus (d - 1) divided by the number of days in the month, times the difference between the CPI-U of two months earlier and of three months earlier. It is truncated to six decimals and rounded to five (31 CFR part 356, appendix B). The reference CPI on this page is computed by 500metrics with that formula from the published CPI-U; Treasury publishes its own figures, which are the ones that apply. The change from a year earlier is ours, rounded to one decimal.

What this number cannot tell you
  • A month with no published CPI-U (October 2025 was never collected, because of the lapse in appropriations) has no change from a year earlier, and no reference CPI is computed from it here.
  • The record begins in January 1913; BLS revises seasonally adjusted figures, not the index shown here.
Observed
Checked by us
Sources and licence

Sources and licence

  • U.S. Bureau of Labor Statistics, Consumer Price Index (source). Licence: Public domain, a work of the US federal government

Our text and compilation: CC BY 4.0. How to reuse and cite this page.