The age determination of latent fingerprint traces is a very important challenge for forensic investigations, which has not been solved satisfyingly so far. Based on prior work, we use the novel and very promising aging feature of counting binary pixel for the approximation of a mathematical aging function to be used for the age determination of latent fingerprint traces. We first show the feasibility of this feature in a test set of nine test series (each comprised of a fingerprint sample scanned continuously over four days) using three different optical sensors (CWL) of the same model and varying resolutions (3,5,10μm). We then approximate the aging function for each test series, showing an average error of approximation between 13% and 40% for an optimal approximation. We discuss the prospects and restrictions of such a function for the age determination of latent fingerprint traces and identify future research challenges.