A system and a method are provided for determining an estimated age of an individual of interest based on images in an image collection. An example system includes a memory for storing computer executable instructions, and a processing unit for accessing the memory and executing the computer executable instructions. The computer executable instructions include an age class estimator to classify a plurality of images of the individual into age classes, each age class corresponding to an interval of age, and each image having a known time stamp, a probability determination engine to determine, for each age class, a value of class probability that an image in the collection falls within the age class, an age determination engine to determine a transition time based on the values of class probability and the known time stamp, and to determine the estimated age of the individual based on the determined transition time.