CPI vs WPI in India: What Each Inflation Measure Tells You

India’s Consumer Price Index (CPI) tracks the retail prices of goods and services bought by households. The Wholesale Price Index (WPI) tracks goods at an earlier transaction stage. Their baskets, weights and price definitions differ, so the two inflation rates can move in opposite directions without either being wrong.

Use CPI when your question is about household purchase prices. Use WPI to track price changes across its goods basket. Neither headline measures every household’s inflation or a particular company’s costs. The MoSPI CPI guide and Office of Economic Adviser’s WPI/PPI manual explain those different scopes.

CPI and WPI: the main differences

The comparison follows the CPI 2024 guidance and June 2026 WPI/PPI release.

CPI has Rural, Urban and Combined series. Keep that label when comparing figures: a national Combined result and a rural result are not interchangeable. Its expenditure weights reflect how spending is distributed across the basket, not how much one particular family spends. The September CPI release reports the three series separately.

WPI is not simply the CPI shopping basket measured one step earlier. It includes goods that households do not buy for final consumption. Its basic-price valuation excludes product taxes and trade and transport margins and includes product subsidies. That differs from the prices households actually pay. CPI methodology; WPI/PPI methodology.

Check the 2026 series, not just the acronym

India introduced CPI with a 2024 reference base on 12 February 2026. The basket and weights draw on the Household Consumption Expenditure Survey 2023–24. The index reference period and the expenditure survey period therefore have different labels; they do different jobs. MoSPI’s new-series release.

The revised WPI, with base 2022–23, was launched on 15 June 2026. Its weighting method uses Gross Value of Output, rather than the older net-traded-value approach. The September 2026 releases retain the new CPI and WPI bases. WPI/PPI launch announcement; September WPI/PPI release.

Older articles may still describe CPI as 2012=100 and WPI as 2011–12=100. Those are historical series, not the current labels. Rebasing can change baskets, weights and methods as well as the reference number. Do not splice old-base and new-base index levels into one growth calculation without an official compatible series or linking method.

WPI, Output PPI and Input PPI are different measures

The June 2026 launch also introduced an Output Producer Price Index, a trial Input Producer Price Index and Service Producer Price Indices. Their names matter:

• Output PPI follows prices received by producers for output, on a basic-price basis.
• Trial Input PPI follows prices paid for representative goods used by manufacturing industry, on a purchaser-price basis. That includes trade and transport margins and non-deductible taxes.
• Service PPIs cover specified service sectors. Their introduction does not turn WPI into an index of goods and services. The Service PPI release notes that its sectors do not cover the whole service economy.

WPI and Output PPI both use basic prices, but they are not interchangeable. The official manual distinguishes their classification frameworks and coverage of export-oriented units. WPI/PPI manual.

A simple example helps: a manufacturer’s factory-gate selling price is an output price. The prices it pays for materials are input prices. A customer buying that manufacturer’s product may use it as an input in another business. The product’s role depends on the transaction, but an output-price index does not thereby become a measure of every buyer’s total costs.

For a particular company, start with its own purchases and cost mix. An aggregate index cannot reveal its wages, finance costs, inventory arrangements or profit margin just because the firm belongs to an industry in the basket.

Why CPI and WPI inflation can diverge

Several differences can matter at once:

• Coverage: CPI includes household services; WPI does not. Some WPI goods are business inputs or equipment rather than household purchases.
• Weights: a price change can have a different influence in a household-spending basket and an output-weighted goods basket.
• Price basis: a producer’s basic price and a consumer’s purchase price include different components.
• Timing: costs, contracts and selling prices need not adjust together. A change in one price does not establish how much will pass through to another, or when.

The government’s comparison of Indian price measures also highlights their different coverage, weights and price concepts. These are reasons to investigate a gap, not a decomposition of an actual month’s results. To explain an observed divergence, examine the relevant components and supporting evidence. Neither index directly measures demand or the volume of goods sold. A price change alone cannot tell you whether demand, supply or both caused it.

A worked example: positive CPI and negative WPI

A hypothetical example shows how the two annual rates can differ:

Each percentage is calculated as (current index ÷ year-earlier index − 1) × 100. The index levels are invented, and comparisons are made only within each row. The example shows how positive consumer inflation and negative wholesale inflation can coexist; it does not estimate the causes of any actual gap. MoSPI’s inflation formula.

For the consumer series, 112.2 ÷ 110.0 − 1 gives 0.02, or 2.0%. For the wholesale series, 118.8 ÷ 120.0 − 1 gives −0.01, or −1.0%. The rates differ by 3.0 percentage points. That difference is not a 3% retail margin, and the two index levels do not show which basket costs more in rupees.

Negative WPI inflation in this example means that its index is below its own year-earlier level. It does not mean every wholesale price fell, or that household prices fell. A lower but still positive year-on-year CPI inflation rate means the increase from a year earlier is smaller. It does not tell you whether the CPI index rose or fell from the previous month.

How to read an Indian inflation release

Before comparing two headline numbers, record:

1. The exact series: CPI Combined, Rural or Urban; WPI; Output PPI; or trial Input PPI.
2. The coverage: all items or a named component. Do not silently substitute a food index for the headline.
3. The reference month and comparison period: year-on-year compares with the same month a year earlier; month-on-month uses the preceding month.
4. The base and version: keep compatible index levels together, particularly across the 2026 changes.
5. The release date and status: distinguish the period measured from the publication date, and provisional observations from final or revised ones.
6. The benchmark: if a report says inflation beat expectations, identify whose forecast, when it was made and whether it covers the same measure and period.

India’s inflation-targeting framework uses headline CPI, not WPI. That makes CPI particularly relevant when reading RBI policy discussion, but one release does not mechanically determine the next interest-rate decision. The RBI’s October 2026 Monetary Policy Report discusses inflation alongside growth, risks and the outlook. Nor does a CPI or WPI number by itself predict the direction of equities, bonds or the rupee.

For any event contract referring to inflation, read its exact index, reference month, source and treatment of revisions. Understanding the statistic does not establish that a matching contract is offered or that a reader is eligible to use a service.

Common questions

Is CPI always higher than WPI?

No. Neither definition fixes the ordering of their inflation rates. Compare changes over the same period, not the raw levels of two differently based indexes.

Does WPI include services now that India has Service PPIs?

No. WPI remains a goods index. The separately published Service PPIs cover specified service sectors; they are not an addition to the WPI basket.

Is WPI published weekly or monthly?

The current WPI is published monthly. Use the dated monthly release and its provisional or final labels rather than applying a schedule from an older series.

Can I subtract WPI inflation from CPI inflation to measure retailers’ margins?

No. A difference between two differently constructed inflation rates does not isolate a retail margin. That would require matched products, prices and costs, rather than two broad index totals.

The practical takeaway

Start with the question you want the data to answer. CPI describes household purchase prices; WPI describes its defined goods-price basket. Output and Input PPIs add distinct producer perspectives. Once you have matched the series, period and release version, a difference becomes something to explain with evidence, rather than a shortcut to margins, demand or a policy forecast.

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Sources and scope

• MoSPI: CPI 2024 questions and inflation formula
• MoSPI: Expert Group Report on CPI
• Office of Economic Adviser: WPI, Output PPI, trial Input PPI and Service PPI manual
• Commerce Ministry: June 2026 WPI/PPI launch
• RBI: Monetary Policy Report, October 2026