What are the key differences between WPI and CPI?

Key differences between Wholesale Price Index (WPI) & Consumer Price Index (CPI) Primary use of WPI is to have inflationary trend in the economy as a whole. However, CPI is used for adjusting income and expenditure streams for changes in the cost of living. WPI is based on wholesale prices for primary articles, administered prices for fuel items and ex-factory prices for manufactured products. On the other hand, CPI is based on retail prices, which include all distribution costs and taxes. Prices for WPI are collected on voluntary basis while price data for CPI are collected by investigators by visiting markets. WPI covers all goods including intermediate goods transacted in the economy while CPI covers only consumer goods and consumer services. WPI weights primarily based on national accounts and enterprise survey data and CPI weights are derived from consumer expenditure survey data.