Headline and core inflation: read the basket before comparing
A headline price measure covers its defined overall basket.
Name the exclusions precisely
A headline price measure covers its defined overall basket. A commonly discussed US core CPI measure excludes food and energy. The exact series label matters: core is not a universal basket definition across all countries or indicators. Excluding items changes the question being measured, not the importance of those expenses to an individual household.
Weighted contributions of 2, 2 and 1.4 percentage points add to a 5.4% toy-basket increase. Other items alone rise 2%. This simplified weighting is not official CPI aggregation.
Open full-size diagram ↗Use a toy weighted basket
Consider an invented fixed-weight basket: food weight 20% with a 10% price increase, energy weight 10% with a 20% increase, and other items weight 70% with a 2% increase. A simple weighted calculation gives 0.20 × 10 + 0.10 × 20 + 0.70 × 2 = 5.4%. Looking only at the remaining other-items component gives 2%. This is a teaching model, not the official CPI aggregation method.
Worked example: Food contribution points: 2; Energy contribution points: 2; Other contribution points: 1.4. Invented values; units follow the row labels and article.
Open full-size diagram ↗Explain the difference without dismissing either number
The two toy results differ because they include different components. Do not subtract core from headline and call the result a household’s energy bill increase. Component weights, index construction and time comparisons affect that relationship. An actual household with different spending weights can experience a different budget change.
Calculation checklist: Toy overall increase: 5.4%; Other-items increase: 2.0%; Weights total: 100%. Preserve these definitions when reproducing the example.
Open full-size diagram ↗Keep period and adjustment aligned
Compare the same month-to-month or twelve-month period and the same adjustment basis. Record the official series identifiers and source date. The currency converter does not adjust purchasing power or calculate a personal inflation rate; these are separate economic concepts.
Sources and conventions
Examples are hypothetical. Worked examples state their formulas and assumptions in the article; our methodology explains the related calculators. Broker contract specifications determine actual lot, margin and execution conditions. These sources document definitions and data; a source link does not imply endorsement of SanForex or a trading service.
These materials are prepared with AI assistance and checked against worked examples and deterministic calculation tests where applicable. They are not an expert suitability assessment or investment advice.
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