This paper aims to quantify airborne fungal load in air-conditioned rooms and develop a health risk rating scale for different indoor environments. Five sampling locations in Kolkata frequented by a heterogeneous human population, containing various types of fungal growth-promoting substances (FGPS) like old documents, food items, waste hair, etc. were chosen as sampling locations where an Andersen Two-Stage Cascade Impactor was ran using Rose Bengal agar and Potato Dextrose agar media plates. Total spore load (CFU/m3), species diversity, species dominance, human exposure time, susceptible age and FGPS were considered the risk factors for this study. A risk rating scale was developed after evaluating the relative importance of these different factors in relation to human health. The most dominant genera were Aspergillus, followed by Penicillium. Maximum CFU was observed at library, followed by computer room. © 2019 Taylor & Francis Group, LLC.