grepcent / static financial knowledge base

Informational only - not investment advice.

Reading Financial Data - Step by Step / Economic indicators

What is CPI?

CPI is an index that tracks prices for a broad consumer basket.

As of: 2026-05-01.

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

  1. Open CPIAUCSL. Its latest observation is 333.979 on 2026-05-01.
  2. Because the base period is 100, 333.979 is about 3.34 times the base-period level.
  3. A basket of goods that cost $100 in the 1982-1984 base period would cost about $333.98 at this CPI level.
  4. A 12-month inflation rate compares the current level with the year-earlier level: 333.979 / 320.62 - 1 = 4.17%.
  5. That tells you the index level. It does not by itself say whether any one person's prices changed by that amount.

See it live

Sources

Informational only - not investment advice.