<p>Dimensions of male genitalia have received considerable scientific attention, but the foreskin has been largely omitted from these efforts. To calculate the foreskin surface area based on measurements of patients or voluntary study participants, we describe the foreskin in a simplified model as a tube of elastic tissue with a minimum length corresponding to that of the glans, and a minimum diameter corresponding to that of the corona in flaccid or erect state. To apply our model, we re-analysed previously collected data from a study of penile measurements. In this study from 2001, genitalia of 143 men aged 18 – 68 were measured in flaccid and erect state. Participants were recruited from secondary schools and hospitals, and penile measurements were performed once on a single day by a single medical doctor. We used this set of data to calculate the foreskin surface area and added 10% to the raw glans measurements to account for functional tissue elasticity. We found a median surface area of 79.8 cm² (Q1 = 63.8 cm², Q3 = 86.6 cm²) and a mean foreskin surface area of 76.2 cm² ± 18.9 cm² (Range 37.6 cm² – 136.8 cm²). We assume that our approximation is rather an underestimation as we did not include the frenulum and foreskin overhang in our calculation. Our re-evaluation of data from an earlier descriptive study using a simplified geometrical model allows an estimation of foreskin surface area, e.g. as a tissue source for reconstructive surgeries. In summary, we present an estimated reference value of 80 cm² (rounded median value) and a simple calculation model for the male foreskin surface area.</p><p></p>