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WPI Price Escalation Calculator
Enter base and current WPI/CPI index values from DPIIT. The calculator applies the component-wise price variation formula used in NHAI GCC Clause 44, MoRTH EPC, and CPWD contracts.
₹
Work executed value in this billing period
Component weightages & index values
Fixed (non-adjustable) portion:%
| Component | Weight (%) | Base index (I₀) | Current index (Iₙ) | Change |
|---|---|---|---|---|
Labour CPI-IW (Consumer Price Index, Industrial Workers) | +5.19% | |||
Material WPI: Construction Materials sub-group | +5.00% | |||
POL (Fuel & Lubricants) WPI: Mineral Oils sub-group | +1.94% | |||
Plant & Equipment WPI: Machinery & Equipment sub-group | +3.45% |
Price variation result
Variable portion
₹37.50 L
75% of bill
Weighted index change
+4.36%
across all components
Price escalation
₹1.64 L
Added to your RA bill
Labour
Material
POL (Fuel & Lubricants)
Plant & Equipment
Formula: PV = R × K × Σ(aᵢ × (Iᵢ − I₀) / I₀) where R = bill amount, K = variable portion, aᵢ = normalised weightage. Per NHAI GCC Cl. 44 / MoRTH PVC.
Where to get the index values: DPIIT publishes WPI sub-group indices on the 14th of every month. eaindustry.nic.in . Your base index (I₀) is the value for the month preceding your tender date. CPI-IW for labour is published by the Labour Bureau.
How the formula works
Fixed and variable portions. Most Indian infrastructure contracts exclude a fixed portion (typically 15–25%) from price adjustment. The remaining variable portion is subject to escalation. NHAI EPC/HAM contracts use 25% fixed under GCC Cl. 44.
Component-wise calculation. The variable portion is split across labour, material, POL, and plant sub-indices using pre-agreed weightages. Each component is adjusted independently using its own WPI/CPI sub-index before summing to a total escalation.
Base index (I₀). The base index is fixed at the time of tendering: the WPI value for the month prior to the tender notice date. This does not change for the life of the contract.
Negative escalation. If current indices are lower than the base (price fall), the formula produces a negative value. This is a deduction from the RA bill; the contractor pays back the benefit of cheaper materials.
CivilBolt calculates this automatically on every RA bill
Connect your contract, and CivilBolt reads the WPI clause, pulls the relevant sub-indices, and computes the escalation amount before you submit each bill.