Reading Financial Data - Step by Step / Economic indicators
What is CPI?
CPI is an index that tracks prices for a broad consumer basket.
Concept
An index is not a dollar amount. CPIAUCSL uses the 1982-1984 average as 100, so the latest number is read against that base. CPI is the level; inflation is the rate of change in that level.
Worked Example: Read the latest CPI observation
- Open CPIAUCSL. Its latest observation is 332.813 on 2026-07-01.
- Because the base period is 100, 332.813 is about 3.33 times the base-period level.
- A basket of goods that cost $100 in the 1982-1984 base period would cost about $332.81 at this CPI level.
- A 12-month inflation rate compares the current level with the year-earlier level: 332.813 / 322.169 - 1 = 3.30%.
- That tells you the index level. It does not by itself say whether any one person's prices changed by that amount.