Construction Material Prices
April 2026: Market estimates
Spot prices for cost awareness. For Clause 70 escalation claims, use the official DPIIT sub-index values below.
WPI All Commodities · YoY
Bitumen VG-30
TMT Steel Fe500D
HSD Diesel
OPC Cement 50kg
River Sand
Market estimates, not official DPIIT values. For claim calculation, use the sub-index links below.
DPIIT release archiveHow NHAI escalation is actually calculated.
WPI-based price escalation under NHAI EPC contracts uses five sub-indices released by DPIIT on the 14th of every month. Most contractors calculate it correctly for the large components and lose money on the small ones.
For your RA bill calculation
Where to get each I value
The remaining 15% is non-escalable: contractor overheads, equipment ownership, and profit. Apply escalation only to the 85% escalable portion.
The Clause 70 formula
The standard NHAI EPC price adjustment formula for each Running Account bill period:
Escalated Amount = P₀ × [0.85 × (Σ Wᴵ × Iᴵ / I₀ᴵ) + 0.15]
Sub-index notes
Standard weightages in NHAI EPC contracts. Check your contract SCC for project-specific deviations; some contracts adjust these for tunnel or bridge work.
Steel and Iron
25%WPI: Iron, Steel and Ferro-alloys (Manufactured Products)
Highest weight in the formula. Covers reinforcement bars, structural steel, and fabricated steel items. The DPIIT series tracks ex-factory prices of major steel producers. TMT bar prices at retail often move faster than the WPI series.
Labour
15%CPI-IW: Consumer Price Index for Industrial Workers (All India)
CPI-IW, not WPILabour escalation uses CPI-IW, not WPI. This is the most common contractor mistake. The CPI-IW series is published by the Labour Bureau, not DPIIT, and is released around the 28th of each month for the previous month. Mixing up WPI and CPI-IW will produce an incorrect claim.
Other Materials
15%WPI: All Commodities (Composite Index)
A catch-all for materials not covered by the other four heads. Uses the overall WPI all-commodities index. Covers aggregates, formwork materials, waterproofing compounds, and minor items. The all-commodities index is more stable than individual commodity series.
Cement
10%WPI: Cement, Lime and Plaster (Manufactured Products)
Cement WPI tracks ex-factory cement prices. Research has found the WPI cement sub-index consistently lags retail spot prices by 3 to 8 percent during high-demand periods. If your actual cement costs exceed the WPI movement significantly, document purchase invoices and consider a Change of Scope claim for the gap.
POL / Bitumen and Diesel
10%WPI: Mineral Oils (Primary Articles or Manufactured Products)
Covers petroleum products including diesel and bitumen. Bitumen tracking is generally more accurate than cement because bitumen prices correlate closely with crude oil, which DPIIT tracks carefully. Diesel prices are administered in India so the WPI series reflects government-set prices, not market prices.
Remaining 15% is non-escalable (fixed overhead, equipment ownership, profit)
Five mistakes that reduce your recovery
Each one is common. Each one costs money.
Wrong base index date
The mistake
Using the contract agreement date or NTP date as the base for I0 instead of the last date of bid submission. The base index must be the WPI/CPI-IW value for the month in which bids were submitted, not when the agreement was signed.
Fix: Check your contract for the specific base date definition. It is usually the month preceding bid submission. If the contract is silent, use the month of bid submission and document your rationale.
Using provisional WPI instead of final
The mistake
DPIIT releases provisional WPI data on the 14th of each month. Final (revised) data for the same month comes approximately 2 months later and can differ by 0.5 to 2 percentage points. Some NHAI contracts specify final data for claim calculation.
Fix: Read your SCC (Special Conditions of Contract) to determine whether the contract requires provisional or final WPI. If the contract is silent, raise a clarification with the IE before your first escalation claim. Using the wrong data series can require claim revisions.
Labour escalation claimed on WPI instead of CPI-IW
The mistake
The 15% labour component uses CPI for Industrial Workers (CPI-IW), published by the Labour Bureau, not the DPIIT WPI series. Contractors who apply WPI to the labour component are calculating an incorrect base and will either over- or under-claim depending on market conditions.
Fix: Download the CPI-IW All India series from the Labour Bureau (labourbureau.gov.in) separately. Apply it only to the labour component. Maintain both DPIIT WPI and Labour Bureau CPI-IW in your escalation workbook.
Skipping escalation on smaller RA bills
The mistake
Escalation must be claimed in every Running Account bill. You cannot consolidate unclaimed escalation from previous bills into a later RA bill as a lump sum. NHAI's IE will reject retrospective lump-sum escalation claims that were not raised on the applicable bill.
Fix: Build escalation calculation into your standard RA bill preparation template. Even when the escalation amount is small, include it. The IE's acceptance of smaller claims also creates a record that the methodology was agreed, which helps when larger claims arise.
Applying escalation to the full RA bill value
The mistake
Clause 70 escalation applies to 85% of the contract value (the escalable portion). The remaining 15% covers contractor overheads, equipment ownership costs, and profit, which are deemed fixed. Applying escalation to 100% of the RA bill overstates the claim and will be rejected.
Fix: Your escalation formula must include the 0.85 multiplier. The standard formula is: Escalated amount = Original amount x [0.85 x (sum of weighted index ratios) + 0.15]. The 0.15 term represents the non-escalable fixed portion.
Data sources and release schedule
Bookmark these. DPIIT provisional data on the 14th. CPI-IW around the 28th.
DPIIT WPI Press Releases
14th of every month (provisional)Monthly WPI press releases with all sub-indices. Download the Excel file for the series data. Filter by 'Manufactured Products' for cement and steel, 'Primary Articles' for some mineral products.
Labour Bureau: CPI-IW
~28th of every monthAll India CPI for Industrial Workers. Required for the 15% labour component of Clause 70. Released around the 28th of each month for the previous month.
MOSPI: Index Numbers
Reference data (not monthly)Ministry of Statistics publishes the official WPI base year data and methodology notes. Use for base year change calculations if your contract spans a WPI base year revision.
WPI base year changes affect long-duration contracts
DPIIT periodically revises the WPI base year (current base: 2011-12). When the base year changes during your contract period, you must apply a linking factor to ensure comparability between the old and new series. MoSPI publishes linking factors. Contracts spanning a base year revision need a variation order to clarify the applicable series.
Escalation is not automatic. You have to claim it, correctly, on every bill.
NHAI does not add escalation to your RA bill on its own. You must calculate and submit it with each bill. A contractor who skips escalation on five consecutive bills cannot retrospectively claim the cumulative amount. The claim must be contemporaneous with the bill period it covers.
Escalation calculated wrong is money left in NHAI's account.
CivilBolt pulls the latest DPIIT WPI and Labour Bureau CPI-IW data and applies the Clause 70 formula to your RA bill values. No spreadsheet errors. No missed months. No wrong base dates.
Prefer to run the numbers yourself? Try the free WPI Escalation Calculator