Solidification of casting is a complex phenomenon which requires accurate input to simulate for real time applications. Interfacial heat transfer coefficient (IHTC) is an important input parameter for the simulation process. The IHTC is varying with respect to time during solidification and the exact value is to be given as input for the accurate simulation of the casting process. In this work an attempt is made to estimate the IHTC during solidification of spherical shaped aluminium alloy component with sand mould. The mould surface heat flux and mould surface temperatures are estimated by inverse control volume technique using the temperature measured at different locations in the mould. The IHTC is calculated using these values. The estimated value of mould surface temperature is validated with the available measured mould temperature at specified location using direct heat conduction problem.