The objective of this study was to use epidemiologic, and infant cadaver drop test data to develop a probabilistic model relating probability of non- displace skull fracture to contact velocity for infants aged up to 6-months. A secondary objective was to verify the accuracy of mass and material scaling methods used in the past to develop head injury tolerance criteria for CRABI-6M dummy. Infant fall data reported in the literature were combined with infant cadaver drop test data to develop a data set of 80 head impacts. Contact velocity for each impact in the data set was estimated from drop height;​ and head acceleration was estimated using pulse width from infant cadaver drop tests. Estimated peak head acceleration was related to probability of skull fracture. Estimated probability was compared with pediatric skull fracture probabilities reported in literature. The curve relating contact velocity with linear skull fracture has the form

P = e^{(-6.5199 + (1.5658V_c))} / (1+ e^{(-6.5199 + (1.5658V_c)) )}

Where V_c is the contact velocity, which in this study, ranges from 1.7 m/s to 4.9 m/s. Probabilities estimated in this study agree with previously reported values thus validating the calculation procedures used in this study.