The Index of Core Industries (ICI) is a concept and a monthly production volume index that measures the combined performance of India's key infrastructure-supportive sectors. The exercise to create the index was initiated in the Office of the Economic Adviser to provide an advance indication of how industries whose output is 'core' to the economy are performing.
The ICI is compiled and published monthly by the Office of Economic Adviser (OEA) under the Department for Promotion of Industry and Internal Trade (DPIIT), Ministry of Commerce and Industry. The index is calculated using the Laspeyre's formula of weighted arithmetic mean of quantity relatives. It serves as a high-frequency lead indicator for the broader Index of Industrial Production (IIP). The core industries' combined weight in the IIP is 32.88% under the latest series, making it a crucial input for policymakers like the Reserve Bank of India (RBI) for forecasting and policy formulation.
The index underwent a major revision in July 2026 to better reflect the current industrial structure. The base year was updated from 2011-12 to 2022-23. The number of core industries expanded from eight to nine with the inclusion of Iron Ore. The nine core industries are: Coal, Crude Oil, Natural Gas, Refinery Products, Fertilisers, Steel, Cement, Electricity, and Iron Ore. Other methodological changes included using Gross Production Data for steel and excluding washed coal and middlings from the coal index to eliminate double counting.