The new series replaces the decade-old WPI with FY11-12 as the base year and is being introduced alongside a broader producer-price measurement framework comprising the output producer price index (OPPI), trial input producer price index (IPPI) and service producer price indices (PPI) covering seven key service sectors.
According to the government, the move is intended to gradually transition India from a wholesale price-based inflation framework to a producer price-based system aligned with international standards and recommendations of the International Monetary Fund (IMF).
The launch of the revised WPI and the new producer price indices represents one of the most significant changes to India's inflation measurement architecture in more than a decade and is expected to provide policymakers and industry with a more comprehensive picture of price movements across the economy.
The office of economic adviser under the department for promotion of industry and internal trade (DPIIT) said the WPI and the newly launched producer price indices would be published in parallel for five years, after which the WPI would be discontinued.
"The transition from WPI to PPI is in alignment with global best practices adopted by advanced economies and the recommendations of the IMF," the ministry said.
Producer price indices are considered a more comprehensive measure of inflation because they capture price movements at the producer level and help assess how increases in input costs are transmitted to output prices.
The government also released service producer price indices for seven sectors in the first phase: banking, securities transactions, insurance, pension fund management, railways, air passenger services and telecommunications.
Wholesale Inflation Accelerates
The first release under the revised series showed wholesale inflation rising to 9.68% year-on-year (y-o-y) in May 2026 from 8.26% in April. The all-commodities index increased to 109.9 in May from 108.8 in the previous month.
Among major categories, inflation in primary articles accelerated to 4.99% in May from 3.78% in April. Fuel and power inflation surged to 30.33% from 24.89%, while manufactured products inflation increased to 7.48% from 6.68%.
The ministry identified mineral oils, crude petroleum and natural gas, chemicals and chemical products, and basic metals as the principal contributors to wholesale inflation during April and May.
Food inflation at the wholesale level also edged higher. The WPI food index recorded inflation of 4.49% in May, compared with 3.11% in April.
The provisional WPI estimate for May was compiled with a weighted response rate of 84.4%, while the final estimate for March was based on a response rate of 97.02%.
Major Changes in the New WPI Series
One of the key features of the revised WPI is the expansion of the commodity basket. The number of items covered has increased from 697 under the FY11-12 series to 957 under the new framework, reflecting changes in production patterns and the broader economy.
The government has also updated the energy basket to better capture developments in India's power sector.
Renewable energy sources such as solar and wind power have been included under the electricity category for the first time. Nuclear power has also been added to the basket.
In another significant change, crude petroleum and natural gas have been moved from the 'primary articles' category to the 'fuel and power' group. According to the ministry, this creates a more coherent structure for tracking energy prices.
The revised methodology uses gross value of output (GVO) to determine commodity weights instead of the net traded value approach used earlier.
Officials said the change provides a more accurate reflection of the economic significance of commodities because weights are now based on domestic production rather than trade flows.
The government has also introduced updated statistical methods for index compilation and handling missing price data. The new series adopts a short-term formulation method for elementary indices and uses targeted mean imputation for missing observations instead of the earlier carry-forward approach.
New Producer Price Indices Introduced
Alongside the revised WPI, the government released the first estimates of the output producer price index and the trial input producer price index.
The output PPI for all commodities stood at 109.6 in May 2026, while the trial input PPI for the manufacturing sector was recorded at 104.9.
The output PPI and service PPI are compiled using basic prices, which exclude taxes and trade margins. In contrast, the trial input PPI is based on purchaser prices because it reflects the cost of inputs acquired by industries.
The weights for these indices have been derived from the supply and use tables of the national accounts for FY22-23.
The ministry said publication of the trial input PPI would initially remain experimental to facilitate data-quality assessment and stakeholder feedback before wider adoption.
Transition Period Planned
To ensure a smooth transition to the producer price framework, the government will continue publishing the WPI for five years.
The next release of the WPI, output PPI and trial input PPI for June 2026 is scheduled for 14 July 2026, while the service producer price indices for Q1FY26-27 will be released on 24 August 2026.
Officials said the parallel publication period would give businesses, policymakers and users sufficient time to adapt to the new framework before the eventual discontinuation of the WPI.
The ministry also cautioned users against directly comparing detailed indices between the old and new series because of substantial changes in commodity coverage and methodology. A linking factor has been provided for major groups to facilitate broad comparisons, although the choice of conversion methodology remains with users.
