This study aimed to predict the shelf life of black soybean Sunsik to develop a functional labeling system for the product. The Arrhenius equation was used to calculate the shelf life by examining alterations in the dietary fiber and calcium levels of black soybean Sunsik stored at 25, 35, and 50°C for 0, 6, and 12 months. Dietary fiber and calcium analyses were performed according to the experimental methods specified in the Food Code of the Ministry of Food and Drug Safety. Both black soybean Sunsik (BS) and black soybean Sunsik containing nondigestible maltodextrin and calcium lactate (BSN) exhibited an upward trend in dietary fiber content after 12 months of storage, compared to their initial levels. During storage, the phytate in Sunsik degraded, releasing cations that facilitated the formation of new cross-links between pectic acid and middle lamella, which ultimately increased dietary fiber content. Conversely, the calcium contents of both BS and BSN decreased with prolonged storage. Based on these findings, the expected shelf life of BS and BSN was calculated as 15.65 and 28.34 months, respectively.