The same fixed-basket index the headline uses, priced every month from January 1998 to August 2026 and set against official CPI on the same unadjusted basis — so the two can be compared at the cadence the Bureau of Labor Statistics publishes.
| Month | RI level | RI YoY | CPI YoY | Gap (bps) | RI MoM | CPI MoM |
|---|---|---|---|---|---|---|
| August 2026 | 548.3 | +4.33% | +3.40% | +94 | +0.31% | +0.32% |
| July 2026 | 546.6 | +4.27% | +3.36% | +91 | +0.06% | -0.01% |
| June 2026 | 546.3 | +4.41% | +3.53% | +88 | -0.29% | -0.35% |
| May 2026 | 547.9 | +5.17% | +4.25% | +92 | +0.75% | +0.63% |
| April 2026 | 543.8 | +4.72% | +3.81% | +91 | +0.81% | +0.85% |
| March 2026 | 539.5 | +4.46% | +3.26% | +120 | +1.23% | +1.05% |
| February 2026 | 532.9 | +3.47% | +2.41% | +105 | +0.41% | +0.47% |
| January 2026 | 530.8 | +3.45% | +2.39% | +106 | +0.45% | +0.37% |
| December 2025 | 528.4 | +3.76% | +2.68% | +109 | +0.13% | -0.02% |
| November 2025 | 527.7 | +3.86% | +2.74% | +113 | +0.17% | -0.10% |
| October 2025 | 526.8 | +3.89% | +2.79% | +110 | -0.05% | -0.10% |
| September 2025 | 527.0 | +4.21% | +3.01% | +119 | +0.28% | +0.25% |
| August 2025 | 525.6 | +4.04% | +2.92% | +112 | +0.25% | +0.29% |
| Bucket | Weight | YoY | MoM |
|---|---|---|---|
| Housing | 35.8% | +3.52% | +0.27% |
| Transportation | 18.1% | +7.01% | +0.37% |
| Discretionary | 13.0% | +2.68% | -0.04% |
| Groceries | 9.8% | +2.19% | -0.04% |
| Health care | 6.5% | +5.56% | +0.45% |
| Utilities | 6.2% | +4.00% | -0.62% |
| Dining out | 5.6% | +3.37% | +0.25% |
| Communications | 2.4% | +1.13% | +2.33% |
| Education | 2.2% | +3.37% | +1.40% |
| Pets | 0.5% | +2.88% | +0.17% |
Same index, finer clock. Each of the ten buckets is priced monthly from the series below, then benchmarked: every calendar year’s twelve readings are scaled so their mean equals the published annual bucket value, with the scaling factor interpolated smoothly between year midpoints so there is no January step. The index is the fixed-2000-basket weighted mean of the ten, exactly as the annual index is. As a result the annual mean of this monthly index reproduces the published annual Reality Index in every year, to three decimals.
Seven buckets from BLS monthly series (not seasonally adjusted): groceries, dining out, utilities, communications, education, discretionary and pets each follow the corresponding CPI component month to month, at the Reality Index’s level.
Housing uses the owner-cost model at monthly resolution: Freddie Mac 30-year rates averaged monthly (a decaying twelve-year vintage of past rates for existing owners, the current rate for new buyers), the FHFA all-transactions house price index, fixed property-tax, insurance and maintenance rates, and the Census homeownership share to blend owners with renters. The renter leg follows the CPI rent index through 2014 and Zillow’s ZORI from 2015.
Transportation is a fixed-weight composite of seven legs: Manheim’s used-vehicle index, gasoline, insurance, maintenance, public transit and vehicle fees from BLS, and — for the monthly shape only — the CPI new-vehicles index, because no contiguous monthly history of transaction prices is public. The annual level, to which the monthly series is benchmarked, carries Kelley Blue Book transaction prices where the annual method uses them.
Health care comes from the KFF employer survey, which is annual; the monthly series interpolates between annual values and carries no monthly signal. It is disclosed here rather than hidden in a footnote because it is 6.5% of the basket.
Disclosures. The series begins in January 1998 because two BLS components (motor-vehicle fees and pets) start in December 1997. BLS published no October 2025 CPI because of the federal shutdown; that month is interpolated in every affected series, as BLS itself does in its year-over-year figures (2025-10, 2025-11). Readings for the current year are provisional until the annual value is published and the year is benchmarked. Month-on-month readings are noisy by nature; the year-over-year rate remains the headline.
Restatement, 23 September 2026. Monthly prints for January to August 2026 were originally built by growing the 2025 annual value of each bucket by its year-over-year change, with the owner side of housing carried forward. Moving to this series changed the January–May readings by 0.13 to 0.23 points and August from +4.87% to +4.33%; June and July were unchanged within 0.05. Each affected brief carries a note.