Nigeria’s inflation trajectory for 2025 has been materially revised upward following the December 2025 Consumer Price Index methodology review by the National Bureau of Statistics, even though the broader disinflation trend remains intact.
A comparison of the CPI year-on-year series published with the November 2025 report and the revised series released in December shows that inflation was higher in every single month from January to November 2025 than previously reported.
The change stems not from fresh price shocks, but from a statistical re-anchoring of the inflation base.
Before December, Nigeria’s year-on-year inflation rates for 2025 were calculated using a single-month reference base under the old 2009 CPI structure. In December, the NBS rebased the CPI and adopted a 12-month average reference period for 2024, setting the average CPI for the year to 100.
According to the bureau, retaining the single-month base would have exaggerated year-on-year inflation due to base effects, particularly at the end of 2025. The revised approach aligns Nigeria’s CPI framework with international best practice and improves stability and comparability over time.
Crucially, the NBS noted that the change affects already released year-on-year inflation rates for January to November 2025, prompting a full recalibration of the inflation path.
The revised CPI series shows a consistent upward adjustment across all months of 2025, with the largest gaps appearing earlier in the year and gradually narrowing toward November.
In January 2025, inflation previously stood at 24.48% but was revised upward to 27.61%, a difference of 3.13 percentage points.
For February, the rate moved from 23.18% to 26.27%, reflecting a 3.09 percentage point increase.
In March, inflation was lifted from 24.23% to 27.35%, while in April was revised from 23.71% to 26.82%, both changes slightly above 3 percentage points.
The pattern continued into May, where inflation rose from 22.97% to 26.06%, and June, which moved from 22.22% to 25.29% under the revised methodology.
By mid-year, the gap began to narrow modestly. July inflation was revised from 21.88% to 24.94%, and August from 20.12% to 23.14%.
In the final quarter, the uplift became smaller but remained significant. September inflation increased from 18.02% to 20.98%, October from 16.05% to 18.97%, while November, initially reported at 14.45%, was revised sharply upward to 17.33%.
Despite the upward revisions, the December CPI report still confirms that inflation eased steadily through 2025. Headline inflation slowed further to 15.15% in December 2025, down from the revised 17.33% in November, reinforcing the downward momentum.
What has changed is the level, not the direction. Under the revised methodology, inflation did not fall as quickly as earlier data suggested, meaning price pressures remained structurally higher for longer across the year.
The recalibration reshapes how Nigeria’s inflation story for 2025 is interpreted. Under the old series, inflation appeared to cool rapidly.
The recalibration reshapes how Nigeria’s inflation story for 2025 is interpreted. Under the old series, inflation appeared to cool rapidly.
The International Monetary Fund (IMF) earlier endorsed Nigeria’s December 2025 inflation outcome and the revised inflation methodology adopted by the NBS, describing the changes as consistent with international best practice and supportive of macroeconomic stability.