Mining operations involve frugal removal of valuable minerals from the earth beneath. Opencast mining is associated with the extraction of large volumes of the earth's crust as overburden to extract valuable minerals. In short-term planning, mining companies estimate the quantity of coal and overburden based on available resources and demand. The industries use both conventional methods as well as advanced software, available in the market, to determine the quantity of in-situ coal and overburden. The present study encompasses a comparison of actual volume excavation in the Manoharpur opencast mine with reference to estimated reserve (coal and overburden) determined by Minex software. The actual pit profile has been determined by conducting a detailed survey using a Terrestrial Laser Scanner (TLS). To generate a pit profile, the survey has been carried out by establishing geo-reference stations using Total Station through closed traverse and generation of point cloud data by setting the TLS over the established geo-reference stations using backsight mode. The volume of opencast excavation has been computed as 19,614,769.99 m3 after processing and de-noising the data using ATLAScan software. The reserve volume of opencast for the financial year 2021–22 has been estimated as 19,386,854.82 m3 using Minex software. A deviation of 1.1% has been obtained which is well within the acceptable range. Integration of the latest technology and instrumentation for such type of sensitive study, involving economic aspects, lead to earning outcome with impeccable accuracy and does not leave room for any ambiguity for the mine operators.