Non-effective width (NEW) of extraction is the width of a depillaring panel, which does not cause any movement on the surface. Extraction of pillars creates an unsupported goaf span which causes caving of the overlying strata with fragments bulking and filling the void. As per the statutory guidelines, the safe limit for different surface features is stipulated with respect to developed horizontal strain due to underground mining. This paper presents the design of NEW of a panel to be extracted using a Continuous Miner-based mechanised depillaring method considering the estimated horizontal strain. The NEW of mechanised depillaring panel is designed considering the geo-mining conditions of the selected mine. Surface subsidence is assessed using an empirical approach and numerical modelling for different pillar extraction techniques. The non-effective width-to-depth ratio of the considered panel is found to be 0.28 to 0.54, which is within the reported value of the past work for the NEW depillaring panel. Surface subsidence is estimated using an empirical formula that varies from 18 mm to 122 mm for 45.6 m to 85.6 m widths of proposed depillaring panels. However, it shows no surface impact as horizontal strain is found to be in the range of 0.10–1.15 mm/m, which is on the lower side of the permissible limit (5mm/m for forest land). Surface subsidence is also examined through three-dimensional numerical modelling for the geo-mining conditions with different methods of pillar extraction techniques and surface subsidence was found to be less than those of the empirical approach. In the pillar goaf method with a 45.6 m panel width, around 1.6 mm subsidence is observed and found to be suitable for NEW depillaring panel. The results of the study revealed that there will be no impact on surface features if the proposed panel is extracted with the goaf pillar method maintaining a 45.6 m depillaring panel width at 160 m depth of cover.