The Wholesale Price Index, or WPI, measures the average change in prices that businesses pay for goods sold in bulk before those goods reach retail shelves. It’s calculated by pricing a fixed, weighted basket of commodities each month and comparing that cost to what the same basket cost in a base year set equal to 100. Because wholesale prices shift before retail prices do, a rising WPI is an early signal that consumer inflation is on the way. India publishes the most prominent WPI still in active use; the United States retired its version in 1978 and replaced it with the Producer Price Index.
What the WPI Measures
The WPI tracks price movements for goods changing hands between producers, wholesalers, and manufacturers. It does not track what households pay at the store. That job belongs to the Consumer Price Index, which reflects spending on groceries, rent, and doctor visits. The WPI stays upstream, focused on raw materials, energy, and factory output moving between businesses.
The practical value of the index is timing. Wholesale prices move before retail prices, so persistent increases in the WPI tend to show up in consumer prices weeks or months later. Central banks and finance ministries treat the index as a leading indicator of supply-side pressure. In India, the Reserve Bank targets CPI for its formal inflation framework but watches WPI closely for signs of cost pressure building in the industrial economy. Fiscal decisions about tariffs, subsidies, and energy policy also lean on wholesale price data to quantify what domestic producers are absorbing.
What’s in the WPI Basket
India’s WPI divides its tracked goods into three groups, each carrying a fixed weight that reflects its share of the industrial economy.1Office of Economic Adviser. Frequently Asked Questions on Revision of Wholesale Price Index (Base 2011-12)
- Primary articles carry a 22.62% weight and cover raw materials including unprocessed food, fibers, and minerals. Prices here swing the most with weather, harvests, and global commodity cycles.
- Fuel and power carry a 13.15% weight and cover electricity, petroleum products, and coal. Because nearly every industrial process depends on energy, changes in this group ripple across the rest of the index.
- Manufactured products carry a 64.23% weight and cover finished and semi-finished goods such as chemicals, metals, machinery, and textiles.
The heavy tilt toward manufactured products means the WPI is best read as a gauge of industrial-sector inflation rather than a broad measure of the whole economy. Services are not in the basket.
How the WPI Is Calculated
Every price index needs a reference point. For the WPI, that reference is a base year set equal to 100. India’s current base year is 2011-12, though a revision to 2022-23 was approved in May 2026 and takes effect in June 2026.2Press Information Bureau, Government of India. Base Year of Wholesale Price Index Revised from 2011-12 to 2022-23 If the index reads 118 for a given month, the tracked basket costs 18% more than it did during the base year.
Each commodity in the basket carries a weight reflecting its share of the national economy, which is why the three top-level groups sum to 100%. A price move in steel shifts the index far more than the same percentage change in a niche chemical. Without weighting, every commodity would count equally and the index would badly misrepresent the actual cost burden on businesses.
The formula itself is the Laspeyres method, a standard approach that compares the current cost of a fixed basket of goods to the cost of that same basket in the base year.3Central Statistics Office, Ireland. Wholesale Price Index – Index Calculation Methodology “Fixed basket” is the working phrase. Between revisions, the items and their weights hold constant, so month-to-month comparisons are apples to apples.
Baskets eventually go stale. When the structure of the economy shifts enough that the old mix no longer represents how industries actually operate, the base year is reset and the weights are redrawn. India has revised its WPI base year seven times since the index began, roughly once a decade.4Ministry of Commerce and Industry. Manual on Wholesale Price Index
Why the United States Doesn’t Publish a WPI
If you’re searching from the United States, there is no current government-published WPI to look up. The Bureau of Labor Statistics called its wholesale-level index the Wholesale Price Index when it launched in 1902, but renamed it the Producer Price Index in 1978.5U.S. Bureau of Labor Statistics. Producer Price Indexes Presentation The rename reflected a real change in what the index measures. Instead of tracking prices at the wholesale transaction stage, the PPI tracks prices received by domestic producers for their output.
The PPI also covers more ground than the traditional WPI model. Where India’s WPI tracks only goods, the U.S. PPI covers nearly all goods-producing sectors (mining, manufacturing, agriculture, forestry, utilities) plus roughly 70% of the service sector’s output, including wholesale and retail trade, transportation, healthcare, finance, and professional services.6U.S. Bureau of Labor Statistics. Producer Price Indexes Concepts That wider scope suits a service-heavy economy. So when analysts discuss “U.S. wholesale prices,” they’re almost always referring to PPI data.
What Moves Wholesale Prices
Global commodity markets drive the largest swings, and energy leads the list. Crude oil feeds into transportation, manufacturing, and power generation, so a jump in international oil prices pushes up costs across most WPI categories at once. These shocks originate outside any single country’s control, but they tend to dominate short-term volatility in the index.
Agricultural output and weather move the primary articles group. A weak monsoon in India or a drought across major grain regions can send wholesale food prices sharply higher. Some of these shifts are seasonal and self-correcting; prolonged disruptions create sustained upward pressure.
Currency exchange rates compound the effect of global prices. When the local currency weakens against the dollar, imported raw materials cost more in local terms even if the dollar-denominated price hasn’t moved. A 10% depreciation can translate almost directly into a 10% rise in the cost of imported inputs at the wholesale level. For economies that import large volumes of oil, metals, or industrial chemicals, this channel is a persistent source of pressure on the index.
Domestic manufacturing conditions round it out. Supply chain disruptions, labor cost changes, and shifts in industrial electricity pricing all feed through to finished goods. When basic metal or chemical input costs rise, manufacturers pass them along, and the WPI captures the cumulative effect.
Where to Find WPI Data
India’s WPI is published monthly by the Office of the Economic Adviser within the Ministry of Commerce and Industry.7Office of Economic Adviser. Office of Economic Adviser Homepage The office posts an advance release calendar so businesses can plan around publication dates. Starting in June 2026, the revised series with base year 2022-23 replaces the 2011-12 series, so anyone comparing older figures against new releases needs to account for the transition.2Press Information Bureau, Government of India. Base Year of Wholesale Price Index Revised from 2011-12 to 2022-23 The headline WPI number includes everything in the basket; a core figure that strips out food and energy is also published, and policymakers tend to watch the core more closely because it filters out the weather- and geopolitics-driven noise that can otherwise mask the underlying trend.