Work out construction escalation cost instantly with clear inputs, formula shown and shareable results.
Because spend is spread across the programme rather than paid on day one, escalation is applied at the mid-point of the construction period: the factor is (1 + rate) raised to half the duration in years. Only the labour and materials share escalates; fixed price subcontracts and imported plant already ordered do not.
Mid-point escalation
Factor = (1 + annual rate)^(months / 24)
Escalation
Amount = base cost x escalatable share x (factor - 1)
Factor = (1 + annual rate)^(months / 24). Because spend is spread across the programme rather than paid on day one, escalation is applied at the mid-point of the construction period: the factor is (1 + rate) raised to half the duration in years.
A cost incurred in month one escalates hardly at all and one in the final month escalates fully. For an evenly spread programme the mid-point average is the right single-figure approximation.
This calculator takes 4 inputs: Base construction cost, Annual escalation rate, Construction duration, Share of cost subject to escalation. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.