Cranial bone thickness and frontal sinus size are important parameters to be known before cranial procedures. Deep-learning systems have become popular for making bulk analyses to diagnose diseases/disorders and plan treatment algorithms in diverse fields of medicine. Deep-learning systems would be valuable assets also for cranial procedures. Deep-learning systems need normative values and variances of the population on which they are used. In the present study, the authors aimed to find out the normative values for skull bone thickness at 4 anatomical locations, and frontal sinus size. the authors also analyzed whether gender affected these values. Consecutive adult female and male patients that had presented to our outpatient and emergency clinics between December 2019 and April 2020 were evaluated. We included 174 patients (98 female and 76 male) into the final analysis. Skull bone thickness was measured in 4 anatomical compartments, and vertical dimension of the left and right frontal sinuses were measured. The mean thickness of frontal, parietal, temporal, and occipital bones was 7.9 mm, 9.7 mm, 6 mm, and 10.1 mm for men; 8.7 mm, 10.2 mm, 6.1 mm, and 10.1 mm for women, respectively. Women had significantly thicker frontal bone when compared to men (P = 0.009). Men had significantly larger frontal sinuses compared to women (16.1 mm versus 13.7 mm for right frontal sinus, P = 0.031; 16.4 mm versus 13.9 mm for left frontal sinus, P = 0.023). Women and men had thicker frontal bone, and larger frontal sinuses, respectively.