Purpose: The Objective Breast Cosmesis Scale (OBCS) is an objective method that documents the aesthetic changes in breast cancer patients. This work evaluates the kOBCS© software (http://www.kobcs.info) which simplifies the estimation of the OBCS values. Methods: Five schematic drawings were photographed and imported into the kOBCS©. Thirty photos of breast cancer patients were imported into kOBCS©; 20 users (experts and non-experts) evaluated the photographs on two different settings. Subjective evaluation was performed using the Harvard breast cosmesis scale. Results: There was a highly significant correlation between the OBCS values based on hand measurements and the values estimated by kOBCS© (r = 0.997, P < 0.001). Agreement among the users using the kOBCS© was strong with high statistical significance (ICC = 0.846, P < 0.001, 95% CI 0.774–0.910, Cronbach’s alpha = 0.991). Results of the subjective analyses and mean OBCS values as estimated by kOBCS© correlated significantly (r = 0.961, P < 0.001). Conclusions: The kOBCS© is a reliable and reproducible easy-to-use software for reporting breast cosmesis following breast-conserving therapy.