Meaning
The Index of Eight Core Industries measures the production performance of eight key infrastructure industries in India.
These industries are called “core” because they form the basic foundation for industrial and economic activity. Their performance affects manufacturing, construction, energy supply, transport, agriculture and overall industrial growth.
The index is released by the Office of the Economic Adviser, Department for Promotion of Industry and Internal Trade, Ministry of Commerce and Industry.
Eight Core Industries
The eight core industries are:
- Coal
- Crude Oil
- Natural Gas
- Petroleum Refinery Products
- Fertilizers
- Steel
- Cement
- Electricity
These sectors together carry 40.27% weight in the Index of Industrial Production with base year 2011–12. This means their performance has a strong influence on overall industrial output.
Weightage
The weights of the eight core industries are:
| Industry | Weight |
| Petroleum Refinery Products | 28.04% |
| Electricity | 19.85% |
| Steel | 17.92% |
| Coal | 10.33% |
| Crude Oil | 8.98% |
| Natural Gas | 6.88% |
| Cement | 5.37% |
| Fertilizers | 2.63% |
Petroleum refinery products have the highest weight, while fertilizers have the lowest weight.
Base Year
The current base year is 2011–12 = 100.
A base year is used as a reference point to compare production growth over time.
Why It Is Important
The index is important because it acts as an early indicator of industrial performance.
It helps in understanding:
- Industrial growth trend
- Infrastructure sector performance
- Energy demand
- Construction activity
- Manufacturing momentum
- Investment climate
- Possible trend in IIP
Since the eight core industries form a large part of IIP, weak performance in these sectors can pull down overall industrial production.
Link with IIP
The Index of Industrial Production measures industrial output across mining, manufacturing and electricity.
The eight core industries are part of IIP and together account for 40.27% of its total weight. Therefore, the core industries index is often seen as an advance signal for IIP trends.
However, it is narrower than IIP because it covers only eight infrastructure sectors.
Latest Trend
As per the latest official release, the combined Index of Eight Core Industries declined by 0.4% in March 2026 compared to March 2025. Production of fertilizers, crude oil, coal and electricity recorded negative growth in March 2026.
For the full financial year April–March 2025–26, the cumulative growth rate of the index was 2.6% on a provisional basis.
Interpretation
A rise in the index suggests expansion in core infrastructure output.
A fall or slowdown may indicate weakness in basic industrial activity.
For example:
- Higher steel and cement output may indicate stronger construction activity.
- Higher electricity output may indicate stronger industrial and household demand.
- Higher fertilizer production may support agriculture.
- Weak coal, crude oil or natural gas output may indicate energy-sector stress.
Limitations
The index is useful, but it has limitations.
It covers only eight industries, not the whole economy.
It measures production, not profitability or employment.
It does not directly capture services sector performance.
It may be affected by seasonal factors, base effect, supply disruptions or global commodity trends.
It gives an early signal, but it should be read along with IIP, PMI, GST collections, power demand, credit growth and investment data.
Conclusion
The Index of Eight Core Industries is a key indicator of India’s infrastructure and industrial performance.
It tracks coal, crude oil, natural gas, refinery products, fertilizers, steel, cement and electricity. Since these sectors have a 40.27% weight in IIP, their performance strongly influences the broader industrial economy.
The latest March 2026 contraction shows short-term weakness in core output, while the full-year growth of 2.6% in 2025–26 suggests moderate overall expansion.
