We use analytics cookies to understand how readers use the site. They only run if you accept. Privacy policy.
Inflation is the rate at which the general price level rises — not the price of any one thing, but a weighted average of nearly everything a household buys. The federal government has measured it since 1913 with the Consumer Price Index, which tracks the cost of a fixed "basket" of goods and services and compares it month to month. When the index rises 3% over a year, the same basket costs 3% more.
Two distinctions matter for reading the news. The first is which gauge — CPI or PCE. The second is which slice — the headline number that includes everything, or "core," which strips out volatile food and energy to show the underlying trend.
Each major group is weighted by how much households actually spend on it. Shelter dominates — which is why housing costs drive the headline number for months after goods prices settle. Approximate CPI-U weights, BLS (2024).