Nigeria’s inflation profile for 2025 has been comprehensively revised upward following a methodological overhaul of the Consumer Price Index (CPI) by the National Bureau of Statistics (NBS), despite clear evidence that inflationary pressures eased steadily toward the end of the year.
The revision follows the CPI rebasing exercise unveiled in December 2025, which altered how year-on-year inflation is calculated. A comparison between the inflation series published with the November 2025 CPI report and the revised figures released in December shows that headline inflation was higher in every month from January to November 2025 than previously reported.
Importantly, the upward adjustments do not reflect new price shocks or a deterioration in economic conditions. Instead, they stem from a statistical re-anchoring of the inflation base, designed to improve accuracy, stability, and international comparability.
What changed in the CPI methodology
Before December 2025, Nigeria’s year-on-year inflation for 2025 was measured using a single-month reference base under the old 2009 CPI framework. Under the revised approach, the NBS rebased the CPI using a 12-month average reference period for 2024, setting the average index level for the year at 100.
According to the bureau, retaining a single-month base would have amplified base effects and exaggerated year-on-year inflation readings, especially toward the end of 2025. The new method aligns Nigeria’s CPI framework with global best practices and reduces volatility in inflation comparisons over time.
Crucially, the shift required a full recalibration of already published inflation data for January to November 2025, resulting in consistently higher reported inflation rates across the year.
Month-by-month revisions show a higher inflation path
Under the revised CPI series, the largest upward adjustments appeared early in 2025 and gradually narrowed as the year progressed.
January inflation was revised upward from 24.48% to 27.61%, a 3.13 percentage point increase. February moved from 23.18% to 26.27%, while March rose from 24.23% to 27.35%. April and May recorded similar adjustments, with inflation revised to 26.82% and 26.06% respectively.
By mid-year, the gap began to close modestly. June inflation increased from 22.22% to 25.29%, July from 21.88% to 24.94%, and August from 20.12% to 23.14%.
In the final quarter, the revisions were smaller but still notable. September inflation was revised from 18.02% to 20.98%, October from 16.05% to 18.97%, and November from 14.45% to 17.33%.
December confirms easing, but from a higher base
Despite the higher historical readings, the December 2025 CPI report confirms that inflation continued to ease. Headline inflation slowed to 15.15% in December, down from the revised 17.33% in November, reinforcing a clear disinflationary trend.
What has changed is not the direction of inflation, but its level. Under the revised framework, inflation remained elevated for longer in 2025 than earlier data suggested, indicating that price pressures were more persistent across the year.
Why the revision matters
The recalibration reshapes how Nigeria’s 2025 inflation narrative is interpreted. Instead of a rapid cooldown, the revised data point to a more gradual disinflation, with inflation remaining above 20% until August and above 18% as late as October.
Still, by December, inflation had moved closer to the Federal Government’s 15% target outlined in the 2025 Appropriation Bill. For policymakers, the revised data support a more cautious assessment of inflation risks when setting interest rates and evaluating real returns. For investors and analysts, it offers a more reliable baseline for comparing Nigeria’s inflation dynamics with regional peers and historical trends.
The International Monetary Fund has endorsed both Nigeria’s December 2025 inflation outcome and the revised CPI methodology, describing the changes as consistent with international best practice and supportive of macroeconomic stability.
Emmanuel Bassey is a Financial Expert that has worked in the Banking and Finance Industry for over 15+ years across different banks in Nigeria
