Relative survival (RS) is an essential statistic for evaluating cancer outcomes utilising data from population-based cancer registries (PBCRs). Despite India having 52 PBCRs, the availability of survival information is constrained, one of the challenges being producing population mortality (PopMort) files required for RS calculations. To address this challenge, we created an Excel-based application (PopMortGen-India) that automates the generation of PopMort files from abridged life tables supplied by India’s Sample Registration System (SRS). The program calculates age- and sex-specific mortality rates by inverting traditional life table formulas and determines survival probabilities for any particular single-year age. The application, developed in Microsoft Excel, employs organised worksheets, formula-driven automation and macros to facilitate the effortless creation of PopMort files, compatible with statistical software such as STATA, R and SAS. ‘PopMortGen-India’ markedly decreases the time needed to produce PopMort files, reducing it from several hours manually to less than 10 minutes for a decade-long dataset. Utilising the life tables of rural Punjab and Maharashtra, PopMort files were generated swiftly and precisely. RS estimates obtained from these files in STATA are closely aligned with published data, including age-standardised RS statistics. The tool offers a quick, precise and scalable method for producing PopMort data vital for RS analysis. Its alignment with manual techniques, coupled with substantial time efficiency, renders it especially appropriate for implementation in resource-limited environments. We propose its formal implementation into PBCR procedures and capacity-building measures to standardise and improve survival statistics among cancer registries in India.