How Nigeria Measures Inflation, and Why the Numbers Suddenly Changed
If you have ever wondered why the official inflation rate does not match what you pay at the market, the answer is partly in how the basket is built.
The National Bureau of Statistics publishes an inflation figure every month, and it is one of the most argued-over numbers in Nigeria. Understanding how it is built explains both why it is useful and why it never quite matches your own experience.
What the CPI is
The Consumer Price Index tracks the price of a fixed basket of goods and services that a typical household buys. Each month the NBS collects prices for the items in that basket across the country, weights them by how much households actually spend on each, and compares the total to a year earlier.
Inflation is the percentage change in that total. Headline inflation covers the whole basket. Food inflation covers the food component. Core inflation strips out food and energy, because those two are volatile and can mask the underlying trend.
Why it never matches your experience
Because the basket is an average of everybody, and nobody is average.
If you spend most of your income on food and transport, your personal inflation rate is closer to the food figure than the headline one. If you own a car and fuel prices jump, your rate is higher than a neighbour who walks. Rural households in the north face a different basket from urban households in Lagos — which is why the NBS publishes separate urban and rural rates.
The official number is not wrong. It simply is not about you specifically.
The January 2025 rebasing
On 18 February 2025, the NBS announced a rebasing of the CPI. This is where a lot of confusion begins.
The old index used 2009 as its base year. Nigerian household spending in 2009 looked substantially different from 2024 — mobile data barely registered, and the weights on several categories no longer reflected reality.
The rebased index uses:
- Price reference (base) year: 2024
- Weight reference period: 2023
- An updated basket of goods and services
The effect on the headline number was dramatic:
| Measure | December 2024 (old basis) | January 2025 (new basis) |
|---|---|---|
| Headline | 34.80% | 24.48% |
| Food | 39.84% | 26.08% |
| Core | — | 22.59% |
| Urban | — | 26.09% |
| Rural | — | 22.15% |
Nothing got cheaper on 18 February 2025. The measuring instrument changed. A rebasing is standard statistical practice and most countries do it every five to ten years; Nigeria's was overdue.
The critical consequence for anyone reading older coverage: figures from January 2025 onwards are not directly comparable with figures before that date. Any chart that runs a continuous line through that point is misleading.
Where inflation sits now
NBS data for August 2026, released 15 September 2026:
- Headline: 15.39% year on year, down from 15.43% in July
- Food: 19.57% year on year, down from 20.31% — the first fall in six months
- Headline month-on-month: 0.71%, down from 1.57%
- Food month-on-month: 1.02%, down sharply from 5.56%
Food inflation was 5.73 percentage points below its August 2025 level of 25.30%.
The month-on-month figures are the more telling ones. A year-on-year rate can fall simply because the comparison month was bad. Month-on-month tells you what is happening right now, and 0.71% is a substantial slowdown.
Why food inflation matters more in the north
Because the share of household income spent on food is higher where incomes are lower. A national headline figure of 15.39% describes an economy. A food figure of 19.57% describes a household budget in Sokoto or Yobe rather more accurately.
Food inflation is also driven by things the CBN cannot influence with interest rates: rainfall, insecurity on farming land, fuel costs in the haulage chain, and border policy.
Frequently asked questions
Does falling inflation mean prices are falling? No. It means prices are rising more slowly. Prices falling outright would be deflation.
Why do the NBS numbers feel too low? Because the basket averages across all households and all regions. Your own spending pattern is probably more food-heavy than the average basket assumes.
Can I compare 2026 inflation to 2022 inflation? Not directly. The CPI was rebased in January 2025 and the two series use different baskets and base years.
Sources
- Rebasing announcement and January 2025 figures — Nairametrics
- August 2026 headline — Channels TV
- August 2026 food inflation — Nairametrics