Closure of the anterior fontanelle is generally accepted to occur within the first two years of life. However, statistical quantification of the precise timing of closure in a Western Australian population has not been explored. The current study examined MDCT scans of 68 individuals between birth and 3.91 years to assess the timing of anterior fontanelle closure. Using OsiriX, the scans are viewed in axial and multi-planar reconstructed (MPR) images and three-dimensional volume rendered reconstructions. Anterior fontanelle fusion status was quantified using two methods: calculating anterior fontanelle area and by taking the oblique linear distances of the open fontanelle. The single greatest proportion of fusion was shown to occur in the first year of life, by which stage only 47.19% of the fontanelle remains unfused (on average by area). There was only one individual demonstrating complete fusion before 1 year of age (0.86 years) with no single individual presenting an open fontanelle beyond 2.4 years of age. The current study outlines statistically quantitated data that facilitates forensic age estimation (either macroscopic or radiographic) specific to Australian individuals from the perinate to early childhood life stages.