BACKGROUND Correlations between selected metric parameters of the human skull and the orbit should be useful for anticipating probable dimensions of the orbit in living subjects. METHODS One hundred human skulls derived from medieval cemeteries in Poland and 20 additional contemporary skulls were investigated. Measurements were made with anthropometric caliper, vernier caliper and lead. RESULTS For orbit depth, orbital coefficient was negatively correlated with the width and length coefficient of the skull, but skull length was positively correlated. The minimal distance between the anterior lacrimal crest and the optic canal had a positive correlation with the skull length and a negative correlation with the orbital coefficient. The distance between the fronto-zygomatic suture and the optic canal had a positive correlation with skull height and with orbit width. The distance between the infraorbital foramen and the optic canal had a negative correlation with the orbital coefficient. Empirical formulas were derived on the basis of the calculated means. These formulas allow prediction of the distances between important orbital structures and topographical points at the orbital entrance, based on skull dimensions which are easily measurable intravitally. CONCLUSIONS We conclude that the actual distances inside the orbit can be determined on the basis of gender, length and height of the skull, the width of the orbit, and the orbital coefficient.